The following are examples of orders of magnitude for different lengths.
Objects of sizes in different order of magnitude.
||Quantum foam (This is a fixed quantity, not a range.)
||Electron, quark, string
|Atomic and cellular
||Atomic nucleus, proton, neutron
||Wavelength of gamma rays and X-rays, hydrogen atom
||DNA helix, virus, wavelength of optical spectrum
||Bacterium, fog water droplet, human hair's diameter[note 1]
||Mosquito, golf ball, domestic cat, violin, viola, football
||Cello, piano, human, automobile, sperm whale, football field, Eiffel Tower
||Mount Everest, length of Panama Canal and Trans-Siberian Railway, larger asteroid
||The Moon, Earth, one light-second
||Sun, one light-minute, Earth's orbit
||Orbits of outer planets, Solar System
||A light-year, the distance to Proxima Centauri
||Milky Way, distance to Andromeda Galaxy
||Huge-LQG, Hercules-Corona Borealis Great Wall, visible universe
To help compare different orders of magnitude, the following list describes various lengths between 1.6×10-35 meters and meters.
Atomic to cellular
Cellular to human scale
Human to astronomical scale
||1 m (exactly)
||Since 1983, defined as length of the path travelled by light in vacuum
during a time interval of 1/299 792 458 of a second. See History of the metre for previous definitions.
||Height of Robert Wadlow, tallest known human being.
||Length of a London bus (AEC Routemaster).
||1 decametre (dam)
||Length of the longest known blue whale.
||Height of the Niagara Falls.
||Height of the Statue of Liberty.
||1 hectometre (hm)
||Length of a typical football field.
|137 m (147 m)
||Height (present and original) of the Great Pyramid of Giza.
||Height of the Eiffel Tower, one of the famous monuments of Paris.
||Height of the Salto Angel, the world's highest free-falling waterfall (Venezuela)
||1 kilometre (km)
||Axial length of the Three Gorges Dam, the largest dam in the world
||Narrowest width of the Strait of Messina, separating Italy and Sicily.
||Height of Mount Everest, the highest mountain on Earth.
||Depth of the Challenger Deep in the Mariana Trench, the deepest known point on Earth's surface.
||Circumference of the Large Hadron Collider, as of May 2010 the largest and highest energy particle accelerator.
||Length of a marathon.
||The distance the IAU considers to be the limit to space, called the Karman line.
||Length of the Suez Canal, connecting the Mediterranean Sea to the Red Sea.
||Length of the Pyrenees, the mountain range separating Spain and France.
||Greatest diameter of the dwarf planet Ceres.
||1,000 km = 1 megametre (Mm)
||2,390 km = 2.39 Mm
||Diameter of dwarf planet Pluto, formerly the smallest planet category[note 2] in the Solar System
|3,480 km= 3.48 Mm
||Diameter of the Moon
|5,200 km = 5.2 Mm
||Typical distance covered by the winner of the 24 Hours of Le Mans automobile endurance race
|6,400 km = 6.4 Mm
||Length of the Great Wall of China
|6,600 km = 6.6 Mm
||Approximate length of the two longest rivers, the Nile and the Amazon
|7,821 km = 7.821 Mm
||Length of the Trans-Canada Highway
|9,288 km = 9.288 Mm
||Length of the Trans-Siberian Railway, longest in the world
||Equatorial diameter of Earth
||Length of Earth's equator
||Diameter of Jupiter
|299.792 km = 299 Mm
||Distance traveled by light in one second
|384,000 km = 384 Mm
||Moon's orbital distance from Earth
||1 million km = 1 gigametre (Gm)
||1,390,000 km = 1.39 Gm
||Diameter of the Sun
|4,800,000 km = 4.8 Gm
||Greatest mileage ever recorded by a car (3 million miles by a 1966 Volvo P-1800S, still driving)
||10 million km
||18 million km
||Approximately one light-minute
||100 million km
||150 million km = 150 Gm
||1 astronomical unit (AU); mean distance between Earth and Sun
|~ 900 Gm
||Optical diameter of Betelgeuse (~600 × Sun)
||1 billion km = 1 terametre (Tm)
||1.4 ×109 km = 1.4 Tm
||Orbital distance of Saturn from Sun
|1.96 ×109 km = 1.96 Tm
||Estimated optical diameter of VY Canis Majoris (1420 × Sun)
|2.3 ×109 km = 2.3 Tm
||Estimated optical diameter of NML Cygni (1650 × Sun)
|2.37 ×109 km = 2.37 Tm
||Median point of the optical diameter of UY Scuti, as of 2016 the largest known star
|5.9 ×109 km = 5.9 Tm
||Orbital distance of Pluto from Sun
|~ 7.5 ×109 km = 7.5 Tm
||Outer boundary of the Kuiper belt, inner boundary of the Oort cloud (~ 50 AU)
||Diameter of the Solar System as a whole
|16.25×109 km = 16.25 Tm
||Distance of the Voyager 1 spacecraft from Sun (as of Feb 2009 ), the farthest man-made object so far
|62.03×109 km = 62.03 Tm
||Estimated radius of the event horizon of the supermassive black hole in NGC 4889, the largest known black hole to date
||1.8×1011 km = 180 Tm
||Size of the debris disk around the star 51 Pegasi 
|2×1011 km = 200 Tm
||Total length of DNA molecules in all cells of an adult human body 
||1 petametre (Pm)
||~ 7.5 ×1012 km = 7.5 Pm
||Supposed outer boundary of the Oort cloud (~ 50,000 AU)
|9.46×1012 km = 9.46 Pm
= 1 light year
|Distance traveled by light in one year; at its current speed, Voyager 1 would need 17,500 years to travel this distance
(3.0857×1013 km = 30.857 Pm)
|4.22 light-years = 39.9 Pm
||Distance to nearest star (Proxima Centauri)
|4.37 light-years = 41.3 Pm
||As of March 2013, distance to nearest discovered extrasolar planet (Alpha Centauri Bc)
||20.4 light-years = 193 Pm
||As of October 2010, distance to nearest discovered extrasolar planet with potential to support life as we know it (Gliese 581 d)
|65 light-years = 6.15×1017 m = 615 Pm
||Approximate radius of humanity's radio bubble, caused by high-power TV broadcasts leaking through the atmosphere into outer space
||1 exametre (Em)
||200 light-years = 1.9 Em
||Distance to nearby solar twin (HIP 56948), a star with properties virtually identical to our Sun 
||1,000 light-years = 9.46 Em or 9.46 × 1015 km
||Average thickness of Milky Way Galaxy (1000 to 3000 ly by 21 cm observations)
||12,000 light-years = 113.5 Em or 1.135 × 1017 km
||Thickness of Milky Way Galaxy's gaseous disk
||Diameter of galactic disk of Milky Way Galaxy
||1 zettametre (Zm)
||Distance to SN 1987A, the most recent naked eye supernova
|52 kiloparsecs = 1.62×1021 m = 1.62 Zm
||Distance to the Large Magellanic Cloud (a dwarf galaxy orbiting the Milky Way)
|54 kiloparsecs = 1.66 Zm
||Distance to the Small Magellanic Cloud (another dwarf galaxy orbiting the Milky Way)
|200 kiloparsecs = 6.15 Zm
||Diameter of the low surface brightness disc halo of the giant spiral galaxy Malin 1
||13.25 Zm = 1.4 million light years
= 600 kiloparsecs
|Radius of the diffuse stellar halo of IC 1101, one of the largest known galaxies
|24 Zm = 2.5 million light-years
= 770 kiloparsecs
|Distance to Andromeda Galaxy
|3.26 million light-years
=30.8 Zm = 1 megaparsec
|50 Zm (1.6 Mpc)
||Diameter of Local Group of galaxies
||300-600 Zm = 10-20 megaparsecs
||Distance to Virgo cluster of galaxies
||1 yottametre (Ym)
||200 million light-years
= 1.9 Ym = 61 megaparsecs
|Diameter of the Local Supercluster and the largest voids and filaments.
|300 million light-years
= 2.8 Ym = 100 megaparsecs
|End of Greatness
|550 million light-years
~170 megaparsecs ~5 Ym
|Diameter of the Horologium Supercluster
|1 billion light-years
= 9.46 Ym =306 megaparsecs
|Diameter of the Pisces-Cetus Supercluster Complex, the supercluster complex where we live.
||1.37 billion light years
= 1.3×1025 m = 13 Ym
|Length of the Sloan Great Wall, a giant wall of galaxies (galactic filament).
|3.26 billion light years
=30.8 Ym = 1 gigaparsec
|4 billion light years
|Length of the Huge-LQG, a group of 73 quasars
= 9.5×1025 m = 95 Ym
|Estimated light travel distance to certain quasars. Length of the Hercules-Corona Borealis Great Wall, a colossal wall of galaxies, the largest and the most massive structure in the observable universe as of 2014.
|13.42 billion light years
=1.27×1026 m = 127 Ym
|Estimated light travel distance to UDFj-39546284, the most distant object ever observed
|9.2×1010 light years
= 8.7×1026 m = 870 Ym
|Approximate diameter (comoving distance) of the visible universe
||130 billion light years
= 1.2×1027 m = 1200 Ym
|Lower bound of the (possibly infinite) radius of the universe, if it is a 3-sphere, according to one estimate using the WMAP data at 95% confidence. It equivalently implies that there are at minimum 21 particle horizon-sized volumes in the universe.
|According to the laws of probability, the distance one must travel until one encounters a volume of space identical to our observable universe with conditions identical to our own.
|Maximum size of universe after cosmological inflation, implied by one resolution of the No-Boundary Proposal
1 yoctometre and less
To help compare different orders of magnitude this section lists lengths shorter than 10-23m (10 ym).
- 1.6 × 10-11yoctometres (1.6 × 10-35 metres) - the Planck length (Measures of distance shorter than this are considered nonsensical and do not make any physical sense, according to current theories of physics).
- 1 ym - 1 yoctometre, the smallest named subdivision of the metre in the SI base unit of length, one septillionth of a metre.
- 1 ym - length of a neutrino.
To help compare different orders of magnitude this section lists lengths between 10-23metres and 10-22 metres (10 ym and 100 ym).
To help compare different orders of magnitude this section lists lengths between 10-22m and 10-21 m (100 ym and 1 zm).
- 100 ym - length of a top quark, one of the smallest known quarks
To help compare different orders of magnitude this section lists lengths between 10-21m and 10-20 m (1 zm and 10 zm).
- 2 zm - length of a preon, hypothetical particles proposed as subcomponents of quarks and leptons; the upper bound for the width of a cosmic string in string theory.
- 2 zm - radius of effective cross section for a 20 GeV neutrino scattering off a nucleon
- 7 zm - radius of effective cross section for a 250 GeV neutrino scattering off a nucleon
To help compare different orders of magnitude this section lists lengths between 10-20m and 10-19 m (10 zm and 100 zm).
- 15 zm - length of a high energy neutrino
- 30 zm - length of a bottom quark
To help compare different orders of magnitude this section lists lengths between 10-19m and 10-18 m (100 zm and 1 am).
To help compare different orders of magnitude this section lists lengths between 10-18m and 10-17 m (1 am and 10 am).
To help compare different orders of magnitude this section lists lengths between 10-17m and 10-16 m (10 am and 100 am).
- 10 am - range of the weak force
To help compare different orders of magnitude this section lists lengths between 10-16m and 10-15 m (100 am and 1 fm).
- 100 am - all lengths shorter than this distance are not conformed in terms of size
- 850 am - approximate proton radius
The femtometre (symbol fm) is a unit of length in the metric system, equal to 10-15metres. In particle physics, this unit is more commonly called a fermi, also with abbreviation "fm". To help compare different orders of magnitude this section lists lengths between 10-15metres and 10-14 metres (1 femtometre (fm) and 10 fm).
To help compare different orders of magnitude this section lists lengths between 10-14m and 10-13 m (10 fm and 100 fm).
To help compare different orders of magnitude, this section lists lengths between 10-13m and 10-12 m (100 fm and 1 pm).
To help compare different orders of magnitude this section lists lengths between 10-12 and 10-11m (1 pm and 10 pm).
To help compare different orders of magnitude this section lists lengths between 10-11 and 10-10m (10 pm and 100 pm).
To help compare different orders of magnitude this section lists lengths between 10-10 and 10-9m (100 pm and 1 nm).
To help compare different orders of magnitude this section lists lengths between 10-9 and 10-8m (1 nm and 10 nm).
To help compare different orders of magnitude this section lists lengths between 10-8 and 10-7m (10 nm and 100 nm).
- 10 nm - 100 angstrom
- 10 nm - side of square of area 10-16 m2
- 10 nm - edge of cube of area 6 * 10-16 m2 and volume 10-24 m3
- 10 nm - radius of circle of area 3.14 * 10-16 m2
- 10 nm - radius of sphere of area 12.56 * 10-16 m2 and volume 4.19 * 10-24 m3
- 10 nm - the average length of a nanowire
- 10 nm - lower size of tobacco smoke
- 11 nm - the average half-pitch of a memory cell speculated to be manufactured in 2015.
- 13 nm - the length of the wavelength that is used for EUV lithography
- 14 nm - Length of a porcine circovirus
- 15 nm - Length of an antibody
- 16 nm - technology is projected to be reached by semiconductor companies in the 2013 timeframe
- 18 nm - diameter of tobacco mosaic virus(Generally, viruses range in size from 20 nm to 450 nm.)
- 20 nm - Length of a nanobe, could be one of the smallest forms of life
- 20 nm to 80 nm - thickness of cell wall in Gram-positive bacteria
- 20 nm - thickness of bacterial flagellum
- 22 nm - the average half-pitch of a memory cell expected to be manufactured at around the 2011-2011 time frame.
- 22 nm - Smallest feature size of production microprocessors in September 2009
- 30 nm - lower size of cooking oil smoke
- 32 nm - the average half-pitch of a memory cell manufactured at around the 2009-2010 time frame.
- 40 nm - extreme ultraviolet wavelength
- 45 nm - the average half-pitch of a memory cell manufactured at around the 2007-2008 time frame.
- 50 nm - upper size for airborne virus particles
- 50 nm - flying height of the head of a hard disk
- 65 nm - the average half-pitch of a memory cell manufactured at around the 2005-2006 time frame.
- 58 nm - height of a T7 bacteriophage
- 90 nm - Length of a HIV virus
- 90 nm - Human immunodeficiency virus (HIV) (generally, viruses range in size from 20 nm to 450 nm)
- 90 nm - the average half-pitch of a memory cell manufactured at around the 2002-2003 time frame.
- 100 nm - Length of a Mesoporous silica.
Comparison of sizes of semiconductor manufacturing process nodes with some microscopic objects and visible light wavelengths. At this scale, the width of a human hair
is about 10 times that of the image.
To help compare different orders of magnitude this section lists lengths between 10-7 and 10-6m (100 nm and 1 ?m).
The silk for a spider's web is around 5-7?m wide.
To help compare different orders of magnitude this section lists some items with lengths between 10-6 and 10-5m (between 1 and 10 micrometres, or ?m).
Fog particles are around 10-50 ?m long.
To help compare different orders of magnitude, this section lists lengths between 10-5m and 10-4 m (10 ?m and 100 ?m).
To help compare different orders of magnitude, this section lists lengths between 10-4m and 10-3 m (100 ?m and 1 mm). The term Myriometre (equivalent to 100 micrometers) is deprecated; the decimal metric prefix myrio- is obsolete and not included among the prefixes when the International System of Units was introduced in 1960.
An average red ant
is about 5 mm long.
To help compare different orders of magnitude this section lists lengths between 10-3m and 10-2 m (1 mm and 1 cm).
To help compare different orders of magnitude this section lists lengths between 10-2m and 10-1 m (1 cm and 10 cm).
An adult human foot
is about 28 centimetres long.
To help compare different orders of magnitude this section lists lengths between 10 centimetres and 100 centimetres (10-1 metre and 1 metre).
10 centimetres (abbreviated to 10 cm) is equal to:
Human-defined scales and structures
- 10.16 cm = 1.016 dm - 1 hand used in measuring height of horses (4 inches)
- 12 cm = 1.2 dm - diameter of a Compact Disc (CD) (= 120 mm)
- 15 cm = 1.5 dm - length of a Bic pen with cap on
- 22 cm = 2.2 dm - diameter of a typical Association football (soccer ball)
- 30 cm = 3 dm - typical school-use ruler length (= 300 mm)
- 30.48 cm = 3.048 dm - 1 foot (measure)
- 60 cm = 6 dm - standard depth (front to back) of a domestic kitchen worktop in Europe (= 600 mm)
- 90 cm = 9 dm - average length of a rapier, a fencing sword
- 91.44 cm = 9.144 dm - one yard (measure)
- 10 cm = 1 dm - diameter of the human cervix upon entering the second stage of labour
- 11 cm = 1.1 dm - diameter of an average potato
- 15 cm = 1.5 dm - approximate size of largest beetle species
- 19 cm = 1.9 dm - length of a banana
- 29 cm = 2.9 dm - length of average human foot
- 29.98 cm = 2.998 dm - distance light travels in one nanosecond
- 31 cm = 3.1 dm - wingspan of largest butterfly species Ornithoptera alexandrae
- 46 cm = 4.6 dm - length of an average domestic cat
- 50 to 65 cm = 5-6.5 dm - a pizote's tail
- 66 cm = 6.6 dm - length of the longest pine cones (produced by the sugar pine)
Leonardo da Vinci drew the Vitruvian Man
within a square of side 1.83 metres and a circle about 1.2 metres in radius
To help compare different orders of magnitude this section lists lengths between one metre and ten metres. Light travels 1 metre in , or 3.3356409519815E-9 of a second.
1 metre is:
Human-defined scales and structures
- 1 m - approximate height of the top part of a doorknob on a door
- 1 m - diameter of a very large beach ball
- 1.435 m - standard gauge of railway track used by about 60% of railways in the world = 4' 8½"
- 2.5 m - distance from the floor to the celling in an average residential house
- 2.7 m - length of the Starr Bumble Bee II, the smallest plane
- 2.77-3.44 m - wavelength of the broadcast radio FM band 87-108 MHz
- 3.05 m - the length of an old Mini
- 8.38 m - the length of a London Bus (Routemaster)
A blue whale
has been measured as 33 metres long; this drawing compares its length to that of a human diver and a dolphin
To help compare different orders of magnitude this section lists lengths between 10 metres and 100 metres.
10 metres (very rarely termed a decametre which is abbreviated as dam) is equal to:
Human-defined scales and structures
- 10 metres - average length of human digestive tract
- 12 metres - length of a whale shark, largest living fish
- 12 metres - wingspan of a Quetzalcoatlus, a pterosaur
- 13 metres - length of a giant squid and colossal squid, the largest living invertebrates
- 15 metres - approximate distance the tropical circles of latitude are moving towards the equator and the polar circles are moving towards the poles each year due to a natural, gradual decrease in the Earth's axial tilt
- 18 metres - height of a Sauroposeidon, the tallest known dinosaur
- 20 metres - length of a Leedsichthys, the largest known fish ever lived
- 21 metres - height of High Force waterfall in England
- 33 metres - length of a blue whale, the largest animal on earth, living or extinct, in terms of mass
- 35 metres - length of a Supersaurus, the longest known dinosaur and longest vertebrate
- 40 metres - average depth beneath the seabed of the Channel tunnel
- 52 metres - height of Niagara Falls
- 83.34 meters - height of a Western hemlock
The Great Pyramid of Giza is 138.8 metres high.
To compare different orders of magnitude this section lists lengths between 100 metres and 1000 metres (1 kilometre).
100 metres (sometimes termed a hectometre) is equal to:
- 328 feet
- one side of a 1 hectare square
- a fifth of a modern li, a Chinese unit of measurement
- the approximate distance travelled by light in 300 nanoseconds
Human-defined scales and structures
- 100 metres - wavelength of the highest mediumwave radio frequency, 3 MHz
- 100 metres - spacing of location marker posts on British motorways
- 138.8 metres - height of the Great Pyramid of Giza (Pyramid of Cheops)
- 139 metres - height of the world's tallest roller coaster, Kingda Ka
- 187 metres- shortest wavelength of the broadcast radio AM band, 1600 kHz
- 202 metres - length of the Széchenyi Chain Bridge connecting Buda and Pest
- 318 meters - height of The New York Times Building
- 318.9 meters - height of the Chrysler Building
- 320.75 metres - height of the Eiffel Tower(including antenna) 
- 328 metres - height of Auckland's Sky Tower, the tallest free-standing structure in the Southern Hemisphere
- 341 metres - height of the world's tallest bridge, the Millau Viaduct
- 390 metres - height of the Empire State Building
- 400-800 metres - approximate heights of the world's tallest skyscrapers of the past 80 years
- 458 metres - length of the Knock Nevis, the world's largest supertanker
- 553.33 meters - height of the CN Tower
- 555 metres - longest wavelength of the broadcast radio AM band, 540 kHz
- 630 metres - height of the KVLY-TV mast, second tallest structure in the world
- 646 metres - height of the Warsaw radio mast, the world's tallest structure until its collapse in 1991
- 828 metres - height of Burj Khalifa, world's tallest structure on 17 January 2009
- 1,000 metres - wavelength of the lowest mediumwave radio frequency, 300 kHz
is 3.776 kilometres (3,776 metres) high
To help compare different orders of magnitude this section lists lengths between 1 kilometre and 10 kilometres (103 and 104metres).
1 kilometre (unit symbol km) is equal to:
Human-defined scales and structures
- 1 km - wavelength of the highest long wave radio frequency, 300 kHz
- 1.280 km - span of the Golden Gate Bridge (distance between towers)
- 1.609 km - 1 mile
- 1.852 km - 1 nautical mile, equal to 1 arc minute of latitude at the surface of the Eearth
- 1.991 km - span of the Akashi Kaiky? Bridge
- 2.309 km - axial length of the Three Gorges Dam, the largest dam in the world
- 3.991 km - length of the Akashi Kaiky? Bridge, longest suspension bridge in the world as of December 2008
- 5.072 km - height of Tanggula Mountain Pass, below highest peak in the Tanggula Mountains, highest railway pass in the world as of August 2005
- 5.727 km - height of Cerro Aucanquilcha, highest road in the world, located in Chile
- 98 airports have paved runways from 4 km to 5.5 km in length.
- 8 km - length of Palm Jebel Ali, an artificial island built off the coast of Dubai
- 9.8 km - length of The World, an artificial archipelago that is also built off the coast of Dubai, whose islands resemble a world map
- 1.637 km - deepest dive of Lake Baikal in Russia, the world's largest fresh water lake.
- 2.228 km - height of Mount Kosciuszko, highest point in Australia
- Most of Manhattan is from 3 to 4 km wide.
- 4.810 km - height of Mont Blanc, highest peak in the Alps
- 4.884 km - height of Carstensz Pyramid, highest peak in Oceania
- 4.892 km - height of Mount Vinson, highest peak in Antarctica
- 5.610 km - height of Mount Damavand, highest peak in Iran
- 5.642 km - height of Mount Elbrus, highest peak in Europe
- 5.895 km - height of Mount Kilimanjaro, highest peak in Africa
- 6.081 km - height of Mount Logan, highest peak in Canada
- 6.194 km - height of Denali, highest peak in North America
- 6.959 km - height of Aconcagua, highest peak in South America
- 7.5 km - depth of Cayman Trench, deepest point in the Caribbean Sea
- 8.848 km - height of Mount Everest, highest peak on Earth, on the border between Nepal and China
To help compare different orders of magnitude this section lists lengths between 10 and 100 kilometres (104 to 105metres). The myriametre (sometimes also spelled myriameter, myriometre and myriometer) (10,000 metres) is a deprecated unit name; the decimal metric prefix myria- (sometimes also written as myrio-) is obsolete and not included among the prefixes when the International System of Units was introduced in 1960.
10 kilometres is equal to:
Human-defined scales and structures
A length of 100 kilometres (about 62 miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the FAI defines spaceflight to begin. To help compare orders of magnitude, this section lists lengths between 100 and 1,000 kilometres (105 and 106metres).
A distance of 100 kilometres is equal to about 62 miles (or 62.13711922 miles).
Human-defined scales and structures
Small planets, the Moon
and dwarf planets
in our solar system have diameters from one to ten million metres. Top row: Mars
(right); bottom row: Moon
(center), and Haumea
(right), to scale.
To help compare different orders of magnitude this section lists lengths starting at 106m (1 Mm or 1,000 km).
1 megametre is equal to:
Human-defined scales and structures
- 1.000 Mm - Length of 1 megameter
- 2.100 Mm - Length of proposed gas pipeline from Iran to India via Pakistan
- 2.100 Mm - Distance from Casablanca to Rome
- 2.288 Mm - Length of the official Alaska Highway when it was built in the 1940s
- 3.069 Mm - Length of Interstate 95 (from Houlton, Maine to Miami, Florida)
- 3.846 Mm - Length of U.S. Route 1 (from Fort Kent, Maine to Key West, Florida)
- 5.000 Mm - Width of the United States
- 5.007 Mm - Estimated length of Interstate 90 (Seattle, Washington to Boston, Massachusetts)
- 5.614 Mm - Length of the Australian Dingo Fence
- 6.4 Mm - Length of the Great Wall of China
- 7.821 Mm - Length of the Trans-Canada Highway, the world's longest national highway (from Victoria, British Columbia to St. John's, Newfoundland)
- 8.836 Mm - Road distance between Prudhoe Bay, Alaska, and Key West, Florida, the endpoints of the U.S. road network
- 8.852 Mm - Aggregate length of the Great Wall of China, including trenches, hills and rivers
- 9.259 Mm - Length of the Trans-Siberian railway
- The Munda Biddi Trail in WA, Australia is over 1000 km long - the world's longest off-road cycle trail
- 1.200 Mm - the length of the Paris-Brest-Paris bicycling event
- Several endurance auto races are, or were, run for 1,000 km:
- 1.000 Mm - Estimated shortest axis of triaxial dwarf planet Haumea
- 1.186 Mm - Diameter of Charon, the largest moon of Pluto
- 1.280 Mm - Diameter of the trans-Neptunian object 50000 Quaoar
- 1.436 Mm - Diameter of Iapetus, one of Saturn's major moons
- 1.578 Mm - Diameter of Titania, the largest of Uranus' moons
- 1.960 Mm - Estimated longest axis of Haumea
- 2.326 Mm - Diameter of the dwarf planet Eris, the largest trans-Neptunian object found to date
- 2.374 Mm - Diameter of Pluto
- 2.707 Mm - Diameter of Triton, largest moon of Neptune
- 3.122 Mm - Diameter of Europa, the smallest Galilean satellite of Jupiter
- 3.476 Mm - Diameter of Earth's Moon
- 3.643 Mm - Diameter of Io, a moon of Jupiter
- 4.821 Mm - Diameter of Callisto, a moon of Jupiter
- 4.879 Mm - Diameter of Mercury
- 5.150 Mm - Diameter of Titan, the largest moon of Saturn
- 5.262 Mm - Diameter of Jupiter's moon Ganymede, the largest moon in the solar system
- 6.366 Mm - Radius of Earth
- 6.792 Mm - Diameter of Mars
Planets from Venus up to Uranus have diameters from ten to one hundred million metres. Top row: Uranus
(right); middle row: Earth
(left), Sirius B
(center), and Venus
(right), to scale.
To help compare different orders of magnitude, this section lists lengths starting at 107metres (10 megametres or 10,000 kilometres).
10 megametres (10 Mm) is
Human-defined scales and structures
To help compare different orders of magnitude, this section lists lengths starting at 108metres (100 megametres or 100,000 kilometres or 62,150 miles).
- 102 Mm - Diameter of HD 149026 b, an unusually dense Jovian planet
- 111.191 Mm - 20,000 (nautical, British) leagues (see Jules Verne, Twenty Thousand Leagues Under the Sea)
- 115 Mm - Width of Saturn's Rings
- 120 Mm - Diameter of ELBM J0555-57Ab, the smallest known star
- 120 Mm - Diameter of Saturn
- 142 Mm - Diameter of Jupiter, the largest planet in the solar system
- 170 Mm - Diameter of TRAPPIST-1, a star recently discovered to have 7 planets around it
- 174 Mm - Diameter of OGLE-TR-122b
- 180 Mm - Average distance covered during life
- 196 Mm - Diameter of Proxima Centauri, a typical red dwarf
- 257 Mm - Diameter of TrES-4
- 272 Mm - Diameter of WASP-12b
- 299.792 Mm - One light second; the distance light travels in vacuum in one second (see speed of light)
- 300 Mm - Diameter of WASP-79b
- 314 Mm - Diameter of CT Cha b
- 384.4 Mm (238,855 mi) - Average Earth-Moon distance
- 671 Mm - Separation between Jupiter and Europa
- 428 Mm - Diameter of GQ Lupi b, one of the largest known planets
- 986 Mm - Diameter of HD 100546 b's surrounding disk.
To help compare different distances this section lists lengths starting at 109metres (1 gigametre (Gm) or 1 billion metres).
Rigel and Aldebaran (top left and right) compared to smaller stars, the Sun (very small dot in lower middle, with orbit of Mercury as yellow ellipse) and transparent sphere with radius of one light minute.
To help compare different distances this section lists lengths starting at 1010metres (10 gigametres (Gm) or 10 million kilometres, or 0.07 Astronomical units).
From largest to smallest: Jupiter's orbit, red supergiant star Betelgeuse, Mars' orbit, Earth's orbit, star R Doradus, and orbits of Venus, Mercury. Inside R Doradus' depiction are the blue giant star Rigel and red giant star Aldebaran. The faint yellow glow around the Sun represents one light minute. Click image to see more details and links to their scales.
To help compare distances at different orders of magnitude this section lists lengths starting at 1011metres (100 Gm or 100 million kilometres or 0.7 astronomical units).
- 109 Gm - 0.7 AU - Distance between Venus and the Sun
- 149.6 Gm (93.0 million mi) - 1.0 AU - Distance between the Earth and the Sun - the definition of the astronomical unit
- 180 Gm - 1.2 AU - Maximum diameter of Sagittarius A*, the supermassive black hole in the center of Milky Way galaxy
- 228 Gm - 1.5 AU - Distance between Mars and the Sun
- 570 Gm - 3.8 AU - Length of the tail of Comet Hyakutake measured by Ulysses; the actual value could be much higher
- 591 Gm - 4.0 AU - Minimum distance between the Earth and Jupiter
- 780 Gm - 5.2 AU - Distance between Jupiter and the Sun
- 947 Gm - 6.4 AU - Diameter of Antares A
- 965 Gm - 6.4 AU - Maximum distance between the Earth and Jupiter
8 things in the Terameter group
Comparison of size of the Kuiper belt (large faint torus) with the star VY Canis Majoris (at its previous estimate, within Saturn's orbit), Betelgeuse (inside Jupiter's orbit) and R Doradus (small central red sphere) together with the orbits of Neptune and Uranus, to scale. The yellow ellipses represent the orbits of each planet and the dwarf planet Pluto.
To help compare different distances, this section lists lengths starting at 1012m (1 Tm or 1 billion km or 6.7 astronomical units).
- 1.079 Tm - 7.2 AU - One light-hour
- 1.4 Tm - 9.5 AU - Distance between Saturn and the Sun
- 1.98 Tm - 13.2 AU - Revised estimated diameter of VY Canis Majoris. The newly improved measurement was 30% lower than the previous 2007 estimate.
- 2.0 Tm - 13.4 AU - Diameter of one of the largest known stars, KY Cygni
- 2.4 Tm - 15.9 AU - Estimated diameter of UY Scuti, the largest known star as of 2013
- 2.9 Tm - 19.4 AU - Distance between Uranus and the Sun
- 3.06 Tm - 20.5 AU - Previous estimated diameter of VY Canis Majoris, as of 2006. The size was revised in 2012 through improved measurement techniques. (see above)
- 4.4 Tm - 29.4 AU - Perihelion distance of Pluto
- 4.5 Tm - 30.1 AU - Distance between Neptune and the Sun
- 4.5 Tm - 30.1 AU - Inner radius of the Kuiper belt
- 5.7 Tm - 38.1 AU - Perihelion distance of Eris
- 7.3 Tm - 48.8 AU - Aphelion distance of Pluto
- 7.5 Tm - 50.1 AU - Outer radius of the Kuiper Belt, inner boundary of the Oort Cloud
Sedna's orbit (left) is longer than 100 Tm, but other lengths are between 10 and 100 Tm: Comet Hale-Bopp
's orbit (lower, faint orange); one light-day
(yellow spherical shell with yellow Vernal point arrow as radius); the heliosphere's termination shock
(blue shell); and other arrows show positions of Voyager 1
(red) and Pioneer 10
(green). Click on image for larger view and links to other scales.
To help compare different distances this section lists lengths starting at 1013m (10 Tm or 10 billion km or 67 astronomical units).
The largest yellow sphere indicates one light month distance from the Sun. Click the image for larger view, more details and links to other scales.
To help compare different distances this section lists lengths starting at 1014m (100 Tm or 100 billion km or 670 astronomical units).
To help compare different distances this section lists lengths starting at 1015m (1 Pm or 1 trillion km or 6685 astronomical units (AU) or 0.11 light years).
- 1.0 Pm = 0.105702341 light years 
- 1.9 Pm ± .5 Pm = 12,000 AU = 0.2 light year radius of Cat's Eye Nebula's inner core
- 4.7 Pm = 30,000 AU = half light year diameter of Bok globule Barnard 68
- 7.5 Pm - 50,000 AU - Possible outer boundary of Oort cloud (other estimates are 75,000 to 125,000 or even 189,000 AU (1.6, 2, and 3 light years, respectively))
- 7.7 Pm - 52,000 AU - Aphelion distance of the Great Daylight Comet of 1910
- 9.5 Pm - 63,241.1 AU - One light year, the distance travelled by light in one year
Objects with size order of magnitude 1e16m: Ten light years (94.6 Pm
) radius circle with yellow Vernal Point arrow; Bubble Nebula (NGC 7635), left; Dumbbell Nebula (NGC 6853), right; one light year shell lower right with the smaller Cat's Eye Nebula (NGC_6543) and Barnard 68 adjacent.
1e16m lengths: Ten light years (94.6 Pm
) yellow shell; Sirius below right; BL Ceti below left; Proxima and Alpha Centauri upper right; light year shell with Comet 1910 A1's orbit inside top right
To help compare different distances this section lists lengths starting at 1016m (10 Pm or 66,800 AU, 1.06 light years).
- 15 Pm - 1.59 light years - Possible outer radius of Oort cloud
- 20 Pm - 2.11 light years - maximum extent of influence of the Sun's gravitational field
- 30.9 Pm - 3.26 light years - 1 parsec
- 39.9 Pm - 4.22 light years - Distance to Proxima Centauri (nearest star to Sun)
- 81.3 Pm - 8.59 light years - Distance to Sirius
Lengths with order of magnitude 1e17m: yellow Vernal Point arrow traces hundred light year radius circle with smaller ten light year circle at right; globular cluster Messier 5 in background; 12 light year radius Orion Nebula middle right; 50 light year wide view of the Carina Nebula bottom left; Pleiades cluster and Bubble nebula with similar diameters each around 10 light years bottom right; grey arrows show distances from Sun to stars Aldebaran (65 light years) and Vega (25 light years).
To help compare different distances this section lists lengths between 1017m (100 Pm or 11 light years) and 1018 m (106 light years).
- 110 Pm - 12 light years - Distance to Tau Ceti
- 230 Pm - 24 light years - Diameter of the Orion Nebula
- 240 Pm - 25 light years - Distance to Vega
- 260 Pm - 27 light years - Distance to Chara, a star approximately as bright as our Sun. Its faintness gives us an idea how our Sun would appear when viewed from even so close a distance as this.
- 350 Pm - 37 light years - Distance to Arcturus
- 373.1 Pm - 39.44 light years - Distance to TRAPPIST-1, a star recently discovered to have 7 planets around it.
- 400 Pm - 42 light years - Distance to Capella
- 620 Pm - 65 light years - Distance to Aldebaran
- 750 Pm - 79.36 light years - Distance to Regulus
- 900 Pm - 92.73 light years - Distance to Algol
Lengths with order of magnitude 1e18m: thousand light year radius circle with yellow arrow and 100 light year circle at right with globular cluster Messier 5 within and Carina Nebula in front; globular cluster Omega Centauri to left of both; part of the 1400 light year wide Tarantula Nebula fills the background.
This list includes distances between 1 and 10 exametres (1018 m). To help compare different distances this section lists lengths between 1018m (1 Em or 105.7 light years) and 1019 m (1057 light years).
To help compare different orders of magnitude, this section lists distances starting at 10 Em (1019m or 1,100 light years).
- 13 Em - 1,300 light years - Distance to the Orion Nebula
- 14 Em - 1,500 light years - Approximate thickness of the plane of the Milky Way galaxy at the Sun's location
- 14.2 Em - 1,520 light years - Diameter of the NGC 604
- 30.8568 Em - 3,261.6 light years - 1 kiloparsec
- 31 Em - 3,200 light years - Distance to Deneb according to Hipparcos
- 46 Em - 4,900 light years - Distance to OGLE-TR-56, the first extrasolar planet discovered using the transit method
- 47 Em - 5,000 light years - Distance to the Boomerang nebula, coldest place known (1 K)
- 53 Em - 5,600 light years - Distance to the globular cluster M4 and the extrasolar planet PSR B1620-26 b within it
- 61 Em - 6,500 light years - Distance to Perseus Spiral Arm (next spiral arm out in the Milky Way galaxy)
- 71 Em - 7,500 light years - Distance to Eta Carinae
To help compare different orders of magnitude, this section lists distances starting at 100 Em (1020m or 11,000 light years).
The zettametre (SI symbol: Zm) is a unit of length in the metric system equal to 1021metres.
To help compare different orders of magnitude, this section lists distances starting at 1 Zm (1021m or 110,000 light years).
To help compare different orders of magnitude, this section lists distances starting at 10 Zm (1022m or 1.1 million light years).
To help compare different orders of magnitude, this section lists distances starting at 100 Zm (1023m or 11 million light years).
The yottametre, or yottameter in the US, ( SI symbol: Ym) is a unit of length in the metric system equal to 1024metres
To help compare different orders of magnitude, this section lists distances starting at 1 Ym (1024m or 105.702 million light years).
The universe within 1 billion light years of Earth
To help compare different orders of magnitude, this section lists distances starting at 10 Ym (1025m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the cosmological models used.
To help compare different orders of magnitude, this section lists distances starting at 100 Ym (1026m or 11 billion light years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.
Distances longer than 100 Ym
- 130 Ym - redshift 6.41 - 13 billion light years - Light travel distance (LTD) to the quasar SDSS J1148+5251
- 130 Ym - redshift 1000 - 13.8 billion light years - Distance (LTD) to the source of the cosmic microwave background radiation; radius of the observable universe measured as a LTD
- 260 Ym - 27.4 billion light years - Diameter of the observable universe (double LTD)
- 440 Ym - 46 billion light years - Radius of the universe measured as a comoving distance.
- 590 Ym - 62 billion light years - Cosmological event horizon: the largest comoving distance from which light will ever reach us (the observer) at any time in the future
- 886.48 Ym - 93.7 billion light years - The diameter of the observable universe; however, there might be unobserved distances that are even greater.
- >1,000 Ym (1 kYm or xennameter in older usage) - Size of universe beyond the cosmic light horizon, depending on its curvature; if the curvature is zero (i.e. the universe is spatially flat), the value can be infinite (see shape of the universe) as previously mentioned
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1,390 miles ... Alaska Route 2 and often treated as a natural extension of the Alaska Highway
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- ^ Richichi, A.; Roccatagliata, V. Aldebaran's angular diameter: How well do we know it?. Astronomy and Astrophysics, Volume 433, Issue 1, 1 April 2005, pp.305-312. "We derive an average value of 19.96±0.03 milliarcsec for the uniform disk diameter. The corresponding limb-darkened value is 20.58±0.03 milliarcsec, or 44.2±0.9 R?."
- ^ Richichi, A. and Roccatagliata, V. derived an angular diameter of 20.58±0.03 milliarcsec, which given a distance of 65 light years yields a diameter of 61 million km
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- ^ radius = distance times sin(angular diameter/2) = 0.2 light year. Distance = 3.3 ± 0.9 kly; angular diameter = 20 arcseconds(Reed et al. 1999)
- ^ Michael Szpir (May-June 2001). "Bart Bok's Black Blobs". American Scientist. Archived from the original on 2003-06-29. Retrieved .
Bok globules such as Barnard 68 are only about half a light-year across and weigh in at about two solar masses
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- ^ diameter=sin(65 arcminutes)*1270 light years=24; where "65.00 x 60.0 (arcmin)" sourced from Revised NGC Data for NGC 1976
- ^ distance × sin( diameter_angle ), using distance of 5kpc (15.8 ± 1.1 kly) and angle 36.3', = 172 ± 12.5 ly.
- ^ van de Ven, G.; van den Bosch, R. C. E.; Verolme, E. K.; de Zeeuw, P. T. (11 January 2006). "The dynamical distance and intrinsic structure of the globular cluster ? Centauri". Astronomy and Astrophysics. 445 (2): 513-543. arXiv:astro-ph/0509228 . Bibcode:2006A&A...445..513V. doi:10.1051/0004-6361:20053061.
best-fit dynamical distance D=4.8±0.3 kpc ... consistent with the canonical value 5.0±0.2 kpc obtained by photometric methods
- ^ a b van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653-664. arXiv:0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
- ^ Harper, Graham M.; Brown, Alexander; Guinan, Edward F. (April 2008). "A New VLA-Hipparcos Distance to Betelgeuse and its Implications" (PDF). The Astronomical Journal. 135 (4): 1430-40. Bibcode:2008AJ....135.1430H. doi:10.1088/0004-6256/135/4/1430.
- ^ Harris, Hugh C.; Dahn, Conard C.; Canzian, Blaise; Guetter, Harry H.; et al. (February 2007). "Trigonometric Parallaxes of Central Stars of Planetary Nebulae". The Astronomical Journal. 133 (2): 631-638. arXiv:astro-ph/0611543 . Bibcode:2007AJ....133..631H. doi:10.1086/510348.
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- ^ Local Group