Length Converter
Convert between any two meter units in your browser — instant, accurate, and private.
Example
1 km = 1,000 m. Switch the unit menus to convert between any pair.
How it works
Every value is converted through a single meter base unit using internationally defined conversion factors, so any from/to pair stays consistent.
Good to know
A length converter earns its keep in the everyday gap between the metric world and the imperial one: reading a European recipe that lists a pan in centimeters, buying lumber sold in feet when your plans are drawn in meters, sizing a TV whose diagonal is quoted in inches against a wall measured in millimeters, or planning a road trip where signs flip between kilometers and miles at the border. The same tool stretches all the way out to a light-year (about 9.46 trillion kilometers, the distance light travels in a year) and all the way down to a nanometer (a billionth of a meter, the scale of viruses and microchip features), so it spans from astronomy to semiconductors.
Most of these units trace back to one of two systems. Kilometer, meter, decimeter, centimeter, millimeter, micrometer, and nanometer are all metric — each just a power-of-ten step from the meter, which is defined by the speed of light. Mile, yard, foot, and inch are imperial/US customary, fixed to metric by exact definition (1 inch = 2.54 cm, 1 foot = 0.3048 m, 1 yard = 0.9144 m, 1 mile = 1.609344 km). The nautical mile (1,852 m) is the odd one out: it comes from navigation, originally one minute of latitude along a meridian, which is why sailors and pilots still use it.
Handy rules of thumb worth memorizing: a meter is a touch longer than a yard (about 3.28 feet, so add roughly 10% to a yard count to get meters); a kilometer is about 0.62 mile, so multiply km by 0.6 for a quick mile estimate, or miles by 1.6 for kilometers. A centimeter is close to a finger's width, an inch is 2.54 cm, and a nautical mile is about 15% longer than a regular ("statute") mile.
The most common mistakes are mixing up the two kinds of mile and trusting too many decimals. Nautical and statute miles differ by roughly 240 meters, which matters in navigation and aviation; never assume "mile" means the same thing in a marine chart as on a road sign. And because units like the light-year and nanometer sit at extreme scales, rounded on-screen results can hide enormous absolute differences — keep extra significant figures whenever you chain conversions or work near the edges of the range.
Frequently asked questions
What does the length converter do?
It converts between common meter units instantly. Pick a unit to convert from and a unit to convert to, type a value, and the result updates live.
Which units does this converter support?
It includes 13 units: Kilometer, Meter, Decimeter, Centimeter, Millimeter, Micrometer, Nanometer, Mile, Yard, Foot, Inch, Nautical mile, Light-year.
Is this converter free and private?
Yes. It runs entirely in your browser, so your inputs never leave your device, there is no sign-up, and it works offline once loaded.
Are the conversions exact?
Conversions use internationally defined factors and are exact where the definitions are exact (for example, 1 inch = 2.54 cm). Displayed results are rounded for readability.
People also ask
How many feet are in a meter?
One meter equals about 3.281 feet, which is 3 feet and roughly 3.37 inches. To go the other way, multiply feet by 0.3048 to get meters.
How many kilometers are in a mile?
One mile equals exactly 1.609344 kilometers. A kilometer is about 0.6214 mile, so for quick mental math multiply miles by 1.6 or kilometers by 0.62.
What is the difference between a nautical mile and a regular mile?
A nautical mile is 1,852 meters, while a statute (land) mile is about 1,609 meters, so the nautical mile is roughly 15% longer. Nautical miles are used in sea and air navigation because one equals about one minute of latitude.
How far is a light-year in kilometers?
One light-year is about 9.46 trillion kilometers (roughly 9,460,000,000,000 km), the distance light travels in one year. In miles that is about 5.88 trillion.
How many millimeters are in an inch?
One inch equals exactly 25.4 millimeters, since an inch is defined as 2.54 centimeters. So 10 mm is about 0.394 inch.
How many centimeters are in a foot?
One foot equals exactly 30.48 centimeters (12 inches at 2.54 cm each). To convert centimeters to feet, divide by 30.48.
How many meters are in a yard?
One yard equals exactly 0.9144 meter, so a yard is a little shorter than a meter. One meter is about 1.094 yards.
How small is a nanometer compared to a millimeter?
A nanometer is one billionth of a meter, and a millimeter is one thousandth of a meter, so one millimeter equals 1,000,000 nanometers. Nanometers are used to measure things like wavelengths of light and microchip features.
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