| +List of Orders of Magnitude for length |
Decade of Length |
Length using SI prefixes |
Length of Item |
Item |
| 10-35 m |
|
1.6×10-35 m |
Planck length; lengths smaller than this do not make any physical sense, according to current theories of physics |
| ... |
| 10-24 m |
1 yoctometre (ym) |
|
|
| 10-21 m |
1 zeptometre (zm) |
|
|
| 10-18 m |
1 attometre (am) |
|
size of a quark |
|
sensitivity of the LIGO detector for gravitational waves |
| 10-15 m |
1 femtometre (fm) |
|
size of a proton |
|
classical electron |
| 10-14 m |
10 fm |
|
scale of the atomic nucleus |
|
range of the weak nuclear force |
| 10-13 m |
100 fm |
|
Compton wavelength of electron |
| 10-12 m |
1 picometre (pm) |
|
distance between atomic nuclei in a white dwarf |
|
wavelength of gamma rays |
| 5 pm |
wavelength of shortest X-rays |
| 10-11 m |
10 pm |
25 pm |
radius of hydrogen atom |
| 31 pm |
radius of helium atom |
| 10-10 m |
100 pm |
|
wavelength of X rays |
| 100 pm |
1 Ångström |
| 100 pm (0.1 nm) |
covalent radius of sulfur atom |
| 126 pm (0.126 nm) |
covalent radius of ruthenium atom |
| 135 pm (0.135 nm) |
covalent radius of technetium atom |
| 153 pm (0.153 nm) |
covalent radius of silver atom |
| 154 pm (0.154 nm) |
length of a typical covalent bond (C-C). |
| 155 pm (0.155 nm) |
covalent radius of zirconium atom |
| 175 pm (0.175 nm) |
covalent radius of thulium atom |
| 225 pm (0.225 nm) |
covalent radius of caesium atom |
| 500 pm (0.50 nm) |
width of protein α helix |
| 10-9 m |
1 nanometre (nm) |
2 nm |
diameter of DNA helix |
| 10-8 m |
10 nm |
20 nm |
thickness of bacterial flagellum |
| 40 nm |
extreme ultraviolet wavelength |
| 90 nm |
human immunodeficiency virus (HIV) (generally, viruses range in size from 20 nm to 450 nm) |
| 100 nm |
90% of particles in wood smoke are smaller than this |
| 10-7 m |
100 nm |
|
size of chromosomes |
| 100 nm |
maximum particle size that can fit through a surgical mask |
| 120 nm |
| 280 nm |
near ultraviolet wavelength |
| 300 nm |
maximum particle size that can fit through a HEPA filter |
| 380-430 nm |
wavelength of violet light -- see color and optical spectrum |
| 430-450 nm |
wavelength of indigo light |
| 450-500 nm |
wavelength of blue light |
| 500-520 nm |
wavelength of cyan light |
| 520-565 nm |
wavelength of green light |
| 565-590 nm |
wavelength of yellow light |
| 590-625 nm |
wavelength of orange light |
| 625-740 nm |
wavelength of red light |
| 10-6 m |
1 micrometre aka micron (µm) |
1-10 µm |
diameter of typical bacterium |
| 1.55 µm |
wavelength of light used in optical fibre |
| 6-8 µm |
diameter of a human red blood cell |
| 6 µm |
anthrax spore |
| 7 µm |
| 7 µm |
diameter of the nucleus of typical eukariotic cell |
| 10-5 m |
10 µm |
10 µm |
typical size of a fog, mist or cloud water droplet |
| 10 µm |
width of cotton fibre |
| 10.6 µm |
wavelength of light emitted by a carbon dioxide laser |
| 12 µm |
width of acrylic fibre |
| 13 µm |
width of nylon fibre |
| 14 µm |
width of polyester fibre |
| 15 µm |
width of silk fibre |
| 17 µm |
| 20 µm |
width of wool fibre |
| 25.4 µm |
1/1000 inch, commonly referred to as 1 mil |
| 50 µm |
typical length of Euglena gracilis, a flagellate protist |
| 80 µm |
average width of human hair (ranges from 18 to 180 µm) |
| 10-4 m |
100 µm |
125 µm |
dust mite |
| 200 µm |
typical length of Paramecium caudatum, a ciliate protist |
| 300 µm |
diameter of Thiomargarita namibiensis, the largest bacterium ever discovered |
| 500 µm |
MEMS micro-engine |
| 500 µm |
diameter of a human ovum |
| 500 µm |
typical length of Amoeba proteus, an amoeboid protist |
| 10-3 m |
1 millimetre (mm) |
2.54 mm |
distance between pins in old DIP (dual-inline-pins) electronic components |
| 5 mm |
length of average red ant |
| 7.62 mm |
common military ammunition size |
| 10-2 m |
1 centimetre (cm) |
1.5 cm |
length of a large mosquito |
| 2.54 cm |
1 inch |
| 3.1 cm |
1 attoparsec (10-18 parsecs) |
| 4.267 cm |
diameter of a golfball |
| 10-1 m |
1 decimetre (dm) |
10 cm |
wavelength of the highest UHF radio frequency, 3 GHz |
| 10 cm |
diameter of the cervix upon entering the second stage of labour |
| 10.16 cm |
Hand using in measuring height of horses (4 inches) |
| 12 cm |
wavelength of the 2.45 GHz ISM radio band |
| 15 cm |
height of a Lilliputian from Gulliver's Travels |
| 30.48 cm |
1 foot |
| 50-65 cm |
a pizote's tail |
| 66 cm |
length of the longest pine cones (produced by the sugar pine) |
| 89 cm |
average adult height of a Hobbit |
| 90 cm |
average length of a rapier, a fencing sword |
| 91 cm |
1 yard |
| 1 m |
1 metre |
1 m |
wavelength of the lowest UHF and highest VHF radio frequency, 300 MHz |
| 1.7 m (5 feet 7 inches) |
average person's height |
| 1.435m |
Standard gauge of railway track |
| 2.77 - 3.44 m |
wavelength of the broadcast radio FM band 108 - 87 MHz |
| 3.048 m (10 feet) |
height of the basket in basketball |
| 5.5 m |
height of tallest animal, the giraffe |
| 10 m |
1 decametre (dam) |
10 m |
wavelength of the lowest VHF and highest shortwave radio frequency, 30 MHz |
| 18.44 m |
distance between the pitcher's rubber and home plate on a baseball field |
| 20 m |
length of a cricket pitch |
| 21 m |
height of High Force waterfall in England. |
| 23 m |
height of the obelisk of the Place de la Concorde, Paris. |
| 25 m |
wavelength of the broadcast radio shortwave band at 12 MHz |
| 27.43 m |
distance between bases on a baseball field |
| 30 m |
length of a blue whale, the largest animal |
| 31 m |
wavelength of the broadcast radio shortwave band at 9.7 MHz |
| 40 m |
average depth beneath the seabed of the Channel tunnel |
| 49 m |
width of an American football field (53 1/3 yards) |
| 49 m |
wavelength of the broadcast radio shortwave band at 6.1 MHz |
| 52 m |
height of Niagara Falls |
| 55 m |
height of the Leaning Tower of Pisa |
| 60 m |
Pyramid of Djoser |
| 70 m |
width of soccer field |
| 70 m |
length of the Bayeux Tapestry |
| 91.44 m |
length of an American football field (100 yards, measured between the goal lines) |
| 100 m |
1 hectometre (hm) |
100 m |
wavelength of the lowest shortwave radio frequency and highest medium wave radio frequency, 3 MHz |
| 105 m |
length of a soccer field |
| 109.73 m |
total length of an American football field (120 yards, including the end zones) |
| 112.34 m |
height of the world's tallest tree, a Coast redwood |
| 137 m |
height of the Great Pyramid of Giza |
| 147 m |
original height of the Great Pyramid of Giza |
| 168 m |
height of the Bungsberg, highest point in Schleswig-Holstein, Germany |
| 187 m |
shortest wavelength of the broadcast radio AM band, 1600 kHz |
| 193 m |
the approximate length of New Jersey State Highway 59 |
| 244 m |
height of the City Gate building in Ramat-Gan, Israel |
| 300 m |
height of the Eiffel Tower |
| 340 m |
distance sound travels in air in one second; see speed of sound |
| 400-500 m |
approximate heights of the world's tallest skyscrapers of the past 70 years. |
| 541 m (1,776 ft) |
height of the planned Freedom Tower at the World Trade Center site |
| 553.33 m |
height of the CN Tower, the world's tallest free-standing land structure |
| 555 m |
longest wavelength of the broadcast radio AM band, 540 kHz |
| 647 m |
height of the Warszawa radio mast, formerly the tallest man-made structure, collapsed in 1991 |
| 1,000 m |
1 kilometre (km) |
1 km |
wavelength of the lowest medium wave radio frequency, 300 kHz |
| 1609 m |
1 international mile |
| 1852 m |
1 nautical mile |
| 8850 m |
height of the highest mountain, Mount Everest |
| 10,000 m |
10 km |
11,518 m |
Mindanao deep |
| 33 km |
narrowest width of the English Channel at the Strait of Dover |
| 100,000 m |
100 km |
111 km |
one degree of latitude on Earth |
| 106 m |
1,000 km = 1 megametre (Mm) |
3,480 km |
diameter of the Moon |
| 6,400 km |
length of the Great Wall of China |
| 107 m |
10,000 km |
12,756 km
40,075 km |
equatorial diameter of the Earth
length of the Earth's equator |
| 108 m |
100,000 km |
384,000 km = 384 Mm |
Moon's orbital distance from Earth |
| 109 m |
1 million km = 1 gigametre (Gm) |
1,390,000 km = 1.39 Gm |
diameter of the Sun |
| 1010 m |
10 million km |
| 1011 m |
100 million km |
150 million km = 150 Gm |
1 astronomical unit (AU); mean distance between Earth and Sun. |
| 1012 m |
1000 million km = 1 terametre (Tm) |
1.4 × 109 km |
orbital distance of Saturn from Sun |
| 5.9 × 109 km = 5.9 Tm |
orbital distance of Pluto from Sun |
| 1013 m |
10 Tm |
13.8 × 109 km = 13.8 Tm |
distance of the Voyager 1 spacecraft from sun (May 2004), the farthest man-made object so far |
| 1014 m |
100 Tm |
| 1015 m |
1 petametre (Pm) |
9.46 × 1012 km = 9.46 Pm = 1 light year |
distance travelled by light in one year |
| 1016 m |
10 Pm |
3.2616 light years (3.08568×1016 m = 30.8568 Pm) |
1 parsec |
| 4.22 light years = 39.9 Pm |
distance to nearest star (Proxima Centauri) |
| 1017 m |
100 Pm |
| 1018 m |
1 exametre (Em) |
| 1019 m |
10 Em |
| 1020 m |
100 Em |
100,000 light years |
diameter of galactic disk of Milky Way Galaxy |
| 1021 m |
1 zettametre (Zm) |
52 kiloparsecs (1.6 × 1021 m = 1.6 Zm) |
distance to the Large Magellanic Cloud (a dwarf galaxy orbiting the Milky Way) |
| 54 kiloparsecs (1.66 × 1021 m = 1.66 Zm) |
distance to the Small Magellanic Cloud (another dwarf galaxy orbiting the Milky Way) |
| 1022 m |
10 Zm |
22.3 Zm (2.36 million light years = 725 kiloparsecs = 22.3 Zm) |
distance to Andromeda Galaxy |
| 50 Zm (1.6 Mpc) |
diameter of Local Group of galaxies |
| 1023 m |
100 Zm |
300-600 Zm (10-20 megaparsecs) |
distance to Virgo cluster of galaxies |
| 1024 m |
1 yottametre (Ym) |
200 million light years (2 Ym, 60 megaparsecs) |
diameter of the Local Supercluster |
| 500 million light years (5 Ym, 150 megaparsecs) |
length of Great Wall, the largest observed superstructure in the universe |
| 1025 m |
10 Ym |
| 1026 m |
100 Ym |
10 × 109 light years |
estimated distance to certain quasars, the farthest observed objects in the universe |
| distance the cosmic background radiation has traveled since the Big Bang |
| 1027 m |