The length converter is a strong and versatile tool for converting between imperial and metric length units. You can easily convert inches, feet, meters, kilometres, and more with 90+ length measurement units. Here is the complete list of units supported by our tool for interconversion:

- Meter [m]
- Kilometer [km]
- Decimeter [dm]
- Centimeter [cm]
- Millimeter [mm]
- Micrometer [µm]
- Nanometer [nm]
- Mile [mi, mi(Int)]
- Yard [yd]
- Foot [ft]
- Inch [in]
- Light year [ly]
- Exameter [Em]
- Petameter [Pm]
- Terameter [Tm]
- Gigameter [Gm]
- Megameter [Mm]
- Hectometer [hm]
- Dekameter [dam]
- Micron [µ]
- Picometer [pm]
- Femtometer [fm]
- Attometer [am]
- Megaparsec [Mpc]
- Kiloparsec [kpc]
- Parsec [pc]
- Astronomical unit [AU, UA]
- League [lea]
- Nautical league (UK)
- Nautical league (int.)
- League (statute) [st.league]
- Nautical mile (UK) [NM (UK)]
- Nautical mile (international)
- Mile (statute) [mi, mi (US)]
- Mile (US survey) [mi]
- Mile (Roman)
- Kiloyard [kyd]
- Furlong [fur]
- Furlong (US survey) [fur]
- Chain [ch]
- Chain (US survey) [ch]
- Roperod [rd]
- Rod (US survey) [rd]
- Perch
- Pole
- Fathom [fath]
- Fathom (US survey) [fath]
- Ell
- Foot (US survey) [ft]
- Link [li]
- Link (US survey) [li]
- Cubit (UK)
- Handspan (cloth)
- Finger (cloth)
- Nail (cloth)
- Inch (US survey) [in]
- Barleycorn
- Mil [mil, thou]
- Microinch
- Angstrom [A]
- A.u. of length [a.u., b]
- X-unit [X]
- Fermi [F, f]
- Arpent
- Pica
- Point
- Twip
- Aln
- Famn
- Caliber [cl]
- Centiinch [cin]
- Ken
- Russian archin
- Roman actus
- Vara de tareja
- Vara conuquera
- Vara castellana
- Cubit (Greek)
- Long reed
- Reed
- Long cubit
- Handbreadth
- Fingerbreadth
- Planck length
- Electron radius (classical)
- Bohr radius [b, a.u.]
- Earth's equatorial radius
- Earth's polar radius
- Earth's distance from the sun
- Sun's radius

This length conversion calculator lets you enter up to 20 units and get real-time results in each unit. If you want to switch to a unit other than our default, click on the unit name and pick it.

With this free online tool, you can confidently solve many measuring difficulties. Why not try the length converter today to simplify your life?

**What is the SI unit of length?**

The SI (International System of Units) unit of length is the meter (symbol is m). It is defined as the length of the path travelled by the light in a vacuum in 1/299,792,458 of a second.

The meter is widely used in scientific and technical contexts around the world and in academia. It is also the basis for many other units of measurement for length, such as the kilometer (1,000 meters), centimeter (0.01 meters), and millimeter (0.001 meters).

**Table of Length Units and Important Details**

Table of Length Units and Important Details (converted to meters)

Unit | Symbol | Conversion to Meters (m) |
---|---|---|

Meter | m | 1 |

Kilometer | km | 1,000 |

Decimeter | dm | 0.1 |

Centimeter | cm | 0.01 |

Millimeter | mm | 0.001 |

Micrometer | µm | 1e-6 |

Nanometer | nm | 1e-9 |

Mile (International) | mi, mi(Int) | 1,609.344 |

Yard | yd | 0.9144 |

Foot | ft | 0.3048 |

Inch | in | 0.0254 |

Light year | ly | 9.4607e+15 |

Exameter | Em | 1e+18 |

Petameter | Pm | 1e+15 |

Terameter | Tm | 1e+12 |

Gigameter | Gm | 1e+9 |

Megameter | Mm | 1e+6 |

Hectometer | hm | 100 |

Dekameter | dam | 10 |

Micron | µ | 1e-6 |

Picometer | pm | 1e-12 |

Femtometer | fm | 1e-15 |

Attometer | am | 1e-18 |

Megaparsec | Mpc | 3.0857e+22 |

Kiloparsec | kpc | 3.0857e+19 |

Parsec | pc | 3.0857e+16 |

Astronomical unit | AU, UA | 149,597,870.7 |

League (UK) | lea | 4,828.032 |

Nautical league (UK) | 5,556 | |

Nautical league (int.) | 5,556 | |

League (statute) | st.league | 4,828.032 |

Nautical mile (UK) | NM (UK) | 1,853.181 |

Nautical mile (international) | 1,852 | |

Mile (statute) | mi, mi (US) | 1,609.344 |

Mile (US survey) | mi | 1,609.347219 |

Mile (Roman) | 1,479.552 |

**Length Units Definitions, Examples, and Use cases**

**Meter [m]**

The meter is the base unit of length in the International System of Units (SI). It is defined as the length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second. The meter is widely used in scientific, engineering, and everyday contexts to express distance, length, or height. For example, a typical car is around 4 meters in length.

Conversion: 1 m = 1 m

**Kilometer [km]**

Kilometer is a unit of length equal to 1,000 meters. It is commonly used in measuring distances between cities or countries. For instance, the distance between New York and Washington D.C. is approximately 360 kilometers.

Conversion: 1 km = 1,000 m

**Decimeter [dm]**

Decimeter is a unit of length equal to one-tenth of a meter or 0.1 meters. It is rarely used in everyday life, but can be useful for expressing measurements in small spaces or for precise measurements in scientific contexts. For example, the length of a pencil is around 15 decimeters.

Conversion: 1 dm = 0.1 m

**Centimeter [cm]**

Centimeter is a unit of length equal to one-hundredth of a meter or 0.01 meters. It is commonly used in everyday contexts to measure small objects or distances, such as the length of a fingernail or the width of a book. For instance, the average length of an adult human fingernail is about 1 centimeter.

Conversion: 1 cm = 0.01 m

**Millimeter [mm]**

Millimeter is a unit of length equal to one-thousandth of a meter or 0.001 meters. It is commonly used to express small measurements or dimensions, such as the thickness of a sheet of paper or the size of a small insect. For example, the diameter of a typical human hair is around 0.1 millimeters.

Conversion: 1 mm = 0.001 m

**Micrometer [µm]**

Micrometer, also known as a micron, is a unit of length equal to one millionth of a meter or 0.000001 meters. It is often used in scientific and engineering contexts to measure very small objects, such as the width of a human hair or the size of a microscopic organism.

Conversion: 1 µm = 0.000001 m

**Nanometer [nm]**

Nanometer is a unit of length equal to one billionth of a meter or 0.000000001 meters. It is commonly used in scientific and technological contexts to express dimensions of small structures or devices, such as the size of individual atoms or the width of a DNA molecule.

Conversion: 1 nm = 0.000000001 m

**Mile [mi, mi(Int)]**

Mile is a unit of length commonly used in the United States and some other countries. It is equal to 5,280 feet or 1,609.344 meters. It is often used to express long distances, such as the distance between two cities or the length of a marathon race. For example, the Boston Marathon has a length of 26.2 miles. Conversion: 1 mi = 1609.344 m

**Yard [yd]**

Yard is a unit of length equal to 3 feet or 0.9144 meters. It is often used in the United States and the United Kingdom to express short distances or lengths of fabrics. For example, a typical football field is around 100 yards in length.

Conversion: 1 yd = 0.9144 m

**Foot [ft]**

Foot is a unit of length equal to one-third of a yard or 0.3048 meters. It is commonly used in the United States and the United Kingdom to express heights or distances. For example, the height of an average doorway is around 6 feet.

Conversion: 1 ft = 0.3048 m

**Inch [in]**

Inch is a unit of length equal to one-twelfth of a foot or 0.0254 meters. It is commonly used in the United States and the United Kingdom to express the dimensions of small objects, such as the length of a nail or the width of a piece of paper. For example, a typical computer screen has a diagonal length of around 24 inches.

Conversion: 1 in = 0.0254 m

**Light year [ly]**

Light year is a unit of length equal to the distance that light travels in one year, which is approximately 9.461 trillion kilometers or 5.878 trillion miles. It is often used in astronomy to express the distances between celestial objects, such as stars or galaxies. For example, the nearest star to our solar system, Proxima Centauri, is located about 4.24 light years away.

Conversion: 1 ly = 9.461 x 10^12 km or 5.878 x 10^12 mi

**Exameter [Em]**

Exameter is a unit of length equal to one quintillion meters or 1 x 10^18 meters. It is an extremely large unit of length and is typically used to express astronomical distances or scales. For example, the diameter of the Milky Way galaxy is estimated to be around 1 exameter.

Conversion: 1 Em = 1 x 10^18 m

**Petameter [Pm]**

Petameter is a unit of length equal to one quadrillion meters or 1 x 10^15 meters. It is often used in scientific and technological contexts to express very large distances or dimensions, such as the size of the universe. For example, the distance between the Earth and the Sun is approximately 150 petameters.

Conversion: 1 Pm = 1 x 10^15 m

**Terameter [Tm]**

Terameter is a unit of length equal to one trillion meters or 1 x 10^12 meters. It is commonly used in scientific and engineering contexts to express large distances or dimensions, such as the size of a continent or the distance between two planets. For example, the distance between the Earth and Mars is approximately 78.3 terameters.

Conversion: 1 Tm = 1 x 10^12 m

**Gigameter [Gm]**

Gigameter is a unit of length equal to one billion meters or 1 x 10^9 meters. It is often used in scientific and technological contexts to express the dimensions of large structures or systems, such as the distance between two cities or the length of a mountain range. For example, the length of the Great Wall of China is estimated to be around 21,196 gigameters.

Conversion: 1 Gm = 1 x 10^9 m

**Megameter [Mm]**

Megameter is a unit of length equal to one million meters or 1 x 10^6 meters. It is commonly used in scientific and engineering contexts to express large distances or dimensions, such as the width of a large river or the distance between two cities. For example, the distance between London and Paris is approximately 3.5 megameters. Conversion: 1 Mm = 1 x 10^6 m

**Hectometer [hm]**

Hectometer is a unit of length equal to one hundred meters or 0.1 kilometers. It is rarely used in everyday contexts, but can be useful for expressing lengths in smaller scales, such as the length of a soccer field or a small street. For example, a typical city block is around 1 hectometer in length.

Conversion: 1 hm = 100 m

**Dekameter [dam]**

Dekameter is a unit of length equal to ten meters or 0.01 kilometers. It is rarely used in everyday contexts, but can be useful for expressing lengths in smaller scales, such as the width of a small park or the length of a building. For example, a typical car is around 4.5 dekameters in length.

Conversion: 1 dam = 10 m

**Micron [µ]**

Micron, also known as a micrometer, is a unit of length equal to one millionth of a meter or 0.000001 meters. It is often used in scientific and engineering contexts to express very small distances or dimensions, such as the width of a thin wire or the size of a virus. Conversion: 1 µ = 0.000001 m

**Picometer [pm]**

Picometer is a unit of length equal to one trillionth of a meter or 0.000000000001 meters. It is commonly used in scientific and technological contexts to express the dimensions of atoms or molecules. For example, the diameter of a hydrogen atom is approximately 53 picometers.

Conversion: 1 pm = 0.000000000001 m

**Femtometer [fm]**

Femtometer is a unit of length equal to one quadrillionth of a meter or 0.000000000000001 meters. It is often used in particle physics to express the dimensions of subatomic particles, such as protons or electrons.

Conversion: 1 fm = 0.000000000000001 m

**Attometer [am]**

Attometer is a unit of length equal to one quintillionth of a meter or 0.000000000000000001 meters. It is an extremely small unit of length and is typically used in scientific and technological contexts to express the dimensions of subatomic particles or the accuracy of measurements.

Conversion: 1 am = 0.000000000000000001 m

**Megaparsec [Mpc]**

Megaparsec is a unit of length equal to one million parsecs or 3.26 million light years. It is often used in astronomy to express the distances between galaxies or clusters of galaxies. For example, the distance between the Milky Way and the Andromeda galaxy is approximately 0.78 megaparsecs.

Conversion: 1 Mpc = 3.26 million ly or 3.09 x 10^22 m

**Kiloparsec [kpc]**

Kiloparsec is a unit of length equal to one thousand parsecs or 3,260 light years. It is often used in astronomy to express the distances between stars or star clusters. For example, the distance between the Sun and the center of the Milky Way galaxy is approximately 8 kiloparsecs.

Conversion: 1 kpc = 3,260 ly or 3.086 x 10^19 m

**Parsec [pc]**

Parsec is a unit of length equal to the distance at which an object would appear to move by one arcsecond when observed from opposite points of the Earth's orbit around the Sun, which is approximately 3.26 light years or 31 trillion kilometers. It is often used in astronomy to express the distances between stars or galaxies. For example, the distance between the Earth and the nearest star, Proxima Centauri, is approximately 1.3 parsecs.

Conversion: 1 pc =3.26 ly or 30.86 trillion km or 3.086 x 10^16 m

**Astronomical unit [AU, UA]**

Astronomical unit is a unit of length equal to the average distance between the Earth and the Sun, which is approximately 149.6 million kilometers or 93 million miles. It is often used in astronomy to express distances within the solar system, such as the distances between planets or the sizes of comets. For example, the distance between the Earth and Mars is approximately 1.52 astronomical units.

Conversion: 1 AU = 149.6 million km or 93 million miles

**League [lea]**

League is a unit of length traditionally used in navigation and seafaring, equal to three nautical miles or 5.56 kilometers. It is rarely used today, but can be useful for expressing distances in marine or coastal contexts. For example, a typical recreational boat can travel around 1 league per hour. Conversion: 1 lea = 5.56 km

**Nautical league (UK)**

Nautical league is a unit of length used in maritime and naval contexts, equal to three nautical miles or 5.56 kilometers. It is used in the United Kingdom and some other countries for expressing distances at sea.

Conversion: 1 nautical league (UK) = 5.56 km

**Nautical league (int.)**

Nautical league is a unit of length used in maritime and naval contexts, equal to three nautical miles or 5.56 kilometers. It is used internationally for expressing distances at sea.

Conversion: 1 nautical league (int.) = 5.56 km

**League (statute) [st.league]**

League is a unit of length traditionally used in the United States, equal to three statute miles or 4.83 kilometers. It is rarely used today, but can be useful for expressing distances in historical or literary contexts. For example, a typical stagecoach in the 19th century could travel around 12 leagues per day.

Conversion: 1 st.league = 4.83 km

**Nautical mile (UK) [NM (UK)]**

Nautical mile is a unit of length used in maritime and naval contexts, equal to one minute of arc along a meridian of the Earth or 1.852 kilometers. It is used in the United Kingdom and some other countries for expressing distances at sea.

Conversion: 1 nautical mile (UK) = 1.852 km

**Nautical mile (international)**

Nautical mile is a unit of length used in maritime and naval contexts, equal to one minute of arc along a meridian of the Earth or 1.852 kilometers. It is used internationally for expressing distances at sea.

Conversion: 1 nautical mile (int.) = 1.852 km

**Mile (statute) [mi, mi (US)]**

Mile is a unit of length used in the United States and some other countries, equal to 5,280 feet or 1,609.344 meters. It is often used to express distances on land or roadways. For example, the length of the famous Route 66 in the United States is approximately 2,400 miles.

Conversion: 1 mi = 1,609.344 m

**Mile (US survey) [mi]**

Mile is a unit of length used in the United States and some other countries, equal to 5,280 feet or 1,609.347 meters. It is often used in land surveying or engineering contexts.

Conversion: 1 mi = 1,609.347 m

**Mile (Roman)**

Mile is a unit of length used in ancient Rome, equal to 1,000 double paces or 1,481 meters. It is rarely used today, but can be useful for expressing distances in historical or archaeological contexts.

Conversion: 1 Roman mile = 1,481 m

**Kiloyard [kyd]**

Kiloyard is a unit of length equal to 1,000 yards or 0.9144 kilometers. It is rarely used in everyday contexts, but can be useful for expressing lengths in smaller scales, such as the length of a small field or a short street.

Conversion: 1 kyd = 914.4 m

**Furlong [fur]**

Furlong is a unit of length traditionally used in agriculture, equal to one-eighth of a mile or 201.168 meters. It is rarely used today, but can be useful for expressing distances in historical or rural contexts. For example, a typical horse race is around 2 furlongs in length.

Conversion: 1 fur = 201.168 m

**Furlong (US survey) [fur]**

Furlong is a unit of length used in the United States land surveying, equal to 660 feet or 201.168 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 fur = 201.168 m

**Chain [ch]**

Chain is a unit of length used in land surveying, equal to 66 feet or 20.1168 meters. It is often used to express distances in rural or agricultural contexts. For example, the size of a typical farm can be around 10 chains by 10 chains.

Conversion: 1 ch = 20.1168 m

**Chain (US survey) [ch]**

Chain is a unit of length used in the United States land surveying, equal to 66 feet or 20.11684023368047 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 ch = 20.11684023368047 m

**Roperod [rd]**

Roperod is a unit of length equal to 16.5 feet or 5.0292 meters. It is an old unit of length that is rarely used today.

Conversion: 1 rd = 5.0292 m

**Rod (US survey) [rd]**

Rod is a unit of length used in the United States land surveying, equal to 16.5 feet or 5.0292 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 rd = 5.0292 m

**Perch**

Perch is a unit of length equal to 16.5 feet or 5.0292 meters. It is an old unit of length that is rarely used today.

Conversion: 1 perch = 5.0292 m

**Pole**

Pole is a unit of length equal to 16.5 feet or 5.0292 meters. It is an old unit of length that is rarely used today.

Conversion: 1 pole = 5.0292 m

**Fathom [fath]**

Fathom is a unit of length used in maritime and naval contexts, equal to six feet or 1.8288 meters. It is often used to express depths or distances underwater. For example, a typical recreational scuba diving depth limit is around 60 fathoms.

Conversion: 1 fath = 1.8288 m

**Fathom (US survey) [fath]**

Fathom is a unit of length used in the United States land surveying, equal to six feet or 1.8288 meters. It is often used to express depths or distances underground.

Conversion: 1 fath = 1.8288 m

**Ell**

Ell is a unit of length used in textile manufacturing, equal to one and a quarter yards or 1.143 meters. It is an old unit of length that is rarely used today.

Conversion: 1 ell = 1.143 m

**Foot (US survey) [ft]**

Foot is a unit of length used in the United States land surveying, equal to one-third of a yard or 0.304800609601219 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 ft = 0.304800609601219 m

**Link [li]**

Link is a unit of length used in land surveying, equal to 7.92 inches or 0.201168 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 li = 0.201168 m

**Link (US survey) [li]**

Link is a unit of length used in the United States land surveying, equal to 7.92 inches or 0.201168 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 li = 0.201168 m

**Cubit (UK)**

Cubit is a unit of length used in ancient times, equal to the distance from the elbow to the tip of the middle finger or approximately 18 inches or 0.4572 meters. It is rarely used today, but can be useful for expressing lengths in historical or archaeological contexts.

Conversion: 1 cubit (UK) = 0.4572 m

**Handspan (cloth)**

Handspan is a unit of length used in textile manufacturing, equal to the width of a hand with the fingers extended, or approximately 9 inches or 0.2286 meters. It is an old unit of length that is rarely used today.

Conversion: 1 handspan (cloth) = 0.2286 m

**Finger (cloth)**

Finger is a unit of length used in textile manufacturing, equal to the width of a finger or approximately 3/4 of an inch or 0.01905 meters. It is an old unit of length that is rarely used today.

Conversion: 1 finger (cloth) = 0.01905 m

**Nail (cloth)**

Nail is a unit of length used in textile manufacturing, equal to the width of a finger nail or approximately 1/16 of an inch or 0.0015875 meters. It is an old unit of length that is rarely used today.

Conversion: 1 nail (cloth) = 0.0015875 m

**Inch (US survey) [in]**

Inch is a unit of length used in the United States land surveying, equal to 1/12 of a foot or 0.0254000508001016 meters. It is often used to express distances in rural or agricultural contexts.

Conversion: 1 in = 0.0254000508001016 m

**Barleycorn**

Barleycorn is a unit of length used in the United Kingdom and United States, equal to one-third of an inch or 0.00846666666666667 meters. It is an old unit of length that is rarely used today.

Conversion: 1 barleycorn = 0.00846666666666667 m

**Mil [mil, thou]**

Mil is a unit of length equal to one-thousandth of an inch or 0.0000254 meters. It is often used in engineering and manufacturing contexts to express very small dimensions, such as the thickness of a wire or the diameter of a pin.

Conversion: 1 mil = 0.0000254 m

**Microinch**

Microinch is a unit of length equal to one millionth of an inch or 0.0000254 micrometers. It is often used in precision engineering and machining to express extremely small dimensions, such as the flatness of a surface or the tolerance of a bearing.

Conversion: 1 microinch = 0.0000254 micrometers

**Angstrom [A]**

Angstrom is a unit of length equal to 0.1 nanometers or 0.0000001 meters. It is often used in physics and chemistry to express the size of atoms and molecules, as well as the wavelength of electromagnetic radiation. For example, the diameter of a hydrogen atom is approximately 1 angstrom.

Conversion: 1 A = 0.0000001 m

**A.u. of length [a.u., b]**

A.u. of length is a unit of length equal to approximately 149.6 million kilometers or the average distance between the Earth and the Sun. It is used in astronomy to express distances within the solar system, such as the sizes of planets and the orbits of comets. For example, the average distance between the Earth and Mars is approximately 1.52 astronomical units.

Conversion: 1 a.u. of length = 149.6 million km

**X-unit [X]**

X-unit is a unit of length equal to approximately 1.0021 angstroms or 0.00000010021 meters. It is often used in X-ray crystallography to express the spacing between atoms in a crystal lattice.

Conversion: 1 X-unit = 0.00000010021 m

**Fermi [F, f]**

Fermi is a unit of length equal to one femtometer or 0.000000000000001 meters. It is often used in nuclear and particle physics to express the size of subatomic particles and their interactions. For example, the diameter of a proton is approximately 1 fermi.

Conversion: 1 fermi = 0.000000000000001 m

**Arpent**

Arpent is a unit of length equal to approximately 191.8 feet or 58.5 meters. It is an old unit of length that was used in France and in some former French colonies.

Conversion: 1 arpent = 58.5 m

**Pica**

Pica is a unit of length equal to approximately 1/6 of an inch or 0.0042333333333333 meters. It is often used in typography to express the size of fonts and the spacing between lines of text.

Conversion: 1 pica = 0.0042333333333333 m

**Point**

Point is a unit of length equal to approximately 1/72 of an inch or 0.0003527777777778 meters. It is often used in typography to express the size of fonts and the spacing between letters.

Conversion: 1 point = 0.0003527777777778 m

**Twip**

Twip is a unit of length equal to 1/20 of a point or 0.0000176388888889 meters. It is a very small unit of length that is often used in digital typography and computer graphics.

Conversion: 1 twip = 0.0000176388888889 m

**Aln**

Aln is a unit of length used in some European countries, equal to approximately 2 feet or 0.59328 meters. It is an old unit of length that is rarely used today.

Conversion: 1 aln = 0.59328 m

**Famn**

Famn is a unit of length used in some European countries, equal to approximately 6 feet or 1.8288 meters. It is an old unit of length that is rarely used today.

Conversion: 1 famn = 1.8288 m

**Caliber [cl]**

Caliber is a unit of length used in firearms, equal to the diameter of the bore of a gun barrel or cartridge. It is often expressed in hundredths or thousandths of an inch, or in millimeters. For example, a typical 9mm handgun has a caliber of approximately 0.35 inches or 9 millimeters.

Conversion: 1 caliber = varies depending on the unit used (e.g. 0.01 inches, 0.25 mm)

**Centiinch [cin]**

Centiinch is a unit of length equal to one-hundredth of an inch or 0.00254 meters. It is often used in precision engineering and machining to express small dimensions, such as the thickness of a metal sheet or the diameter of a small hole.

Conversion: 1 centiinch = 0.00254 m

**Ken**

Ken is a unit of length used in Japan, equal to 6 shaku or 1.81818 meters. It is an old unit of length that is rarely used today.

Conversion: 1 ken = 1.81818 m

**Russian archin**

Russian archin is a unit of length used in Russia, equal to approximately 71.12 centimeters or 0.7112 meters. It is an old unit of length that is rarely used today.

Conversion: 1 Russian archin = 0.7112 m

**Roman actus**

Roman actus is a unit of length used in ancient Rome, equal to approximately 120 Roman feet or 35.5 meters. It is an old unit of length that is rarely used today.

Conversion

1 Roman actus = 35.5 m

**Vara de tareja**

Vara de tareja is a unit of length used in Spain, equal to approximately 835 millimeters or 0.835 meters. It is an old unit of length that is rarely used today.

Conversion: 1 vara de tareja = 0.835 m

**Vara conuquera**

Vara conuquera is a unit of length used in some Latin American countries, equal to approximately 84 inches or 2.1336 meters. It is an old unit of length that is rarely used today.

Conversion: 1 vara conuquera = 2.1336 m

**Vara castellana**

Vara castellana is a unit of length used in Spain and some Latin American countries, equal to approximately 33 inches or 0.835 meters. It is an old unit of length that is rarely used today.

Conversion: 1 vara castellana = 0.835 m

**Cubit (Greek)**

Cubit (Greek) is a unit of length used in ancient Greece, equal to approximately 1.5 feet or 0.4572 meters. It is an old unit of length that is rarely used today.

Conversion: 1 cubit (Greek) = 0.4572 m

**Long reed**

Long reed is a unit of length used in ancient Egypt, equal to approximately 10.5 feet or 3.2 meters. It is an old unit of length that is rarely used today.

Conversion: 1 long reed = 3.2 m

**Reed**

Reed is a unit of length used in ancient Egypt, equal to approximately 7 feet or 2.1336 meters. It is an old unit of length that is rarely used today. Conversion: 1 reed = 2.1336 m

**Long cubit**

Long cubit is a unit of length used in ancient Egypt and the Middle East, equal to approximately 21 inches or 0.5334 meters. It is an old unit of length that is rarely used today.

Conversion: 1 long cubit = 0.5334 m

**Handbreadth**

Handbreadth is a unit of length used in ancient times, equal to the width of four fingers or approximately 3 inches or 0.0762 meters. It is an old unit of length that is rarely used today.

Conversion: 1 handbreadth = 0.0762 m

**Fingerbreadth**

Fingerbreadth is a unit of length used in ancient times, equal to the width of one finger or approximately 0.75 inches or 0.01905 meters. It is an old unit of length that is rarely used today.

Conversion: 1 fingerbreadth = 0.01905 m

**Planck length**

Planck length is a unit of length derived from fundamental physical constants, equal to approximately 1.616 x 10^-35 meters. It is the smallest possible length that can be physically meaningful, and is often used in theoretical physics to study the structure of space-time.

Conversion: 1 Planck length = 1.616 x 10^-35 m

**Electron radius (classical)**

Electron radius (classical) is a unit of length derived from the classical theory of electromagnetism, equal to approximately 2.8179 x 10^-15 meters. It represents the radius of an electron in an atom in its ground state. It is often used in atomic physics and quantum mechanics.

Conversion: 1 electron radius (classical) = 2.8179 x 10^-15 m

**Bohr radius [b, a.u.]**

Bohr radius is a unit of length derived from quantum mechanics, equal to approximately 5.2918 x 10^-11 meters. It represents the radius of the electron's orbit in a hydrogen atom in its ground state. It is often used in atomic physics and chemistry.

Conversion: 1 Bohr radius = 5.2918 x 10^-11 m

**Earth's equatorial radius**

Earth's equatorial radius is a unit of length equal to the distance from the center of the Earth to its equator, approximately 6,378.1 kilometers or 6,378,137 meters. It is often used in geodesy and earth sciences. Conversion:

1 Earth's equatorial radius = 6,378,137 m

**Earth's polar radius**

Earth's polar radius is a unit of length equal to the distance from the center of the Earth to its North or South Pole, approximately 6,356.8 kilometers or 6,356,752.3142 meters. It is often used in geodesy and earth sciences.

Conversion: 1 Earth's polar radius = 6,356,752.3142 m

**Earth's distance from the sun**

Earth's distance from the sun is a unit of length equal to the average distance between the Earth and the Sun, approximately 149.6 million kilometers or 149.6 x 10^9 meters. It is often used in astronomy and astrophysics.

Conversion: 1 Earth's distance from the sun = 149.6 x 10^9 m

**Sun's radius**

Sun's radius is a unit of length equal to the distance from the center of the Sun to its surface, approximately 695,700 kilometers or 695,700,000 meters. It is often used in astronomy and astrophysics.

Conversion: 1 Sun's radius = 695,700,000 m