Length Converter

Convert length and distance between metric and imperial units, millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles. Calculates in your browser.

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About length conversions

Enter a value and choose the units to convert between. Each length unit is defined against a single base unit, so any pair lines up consistently, the table shows your value in every length unit at once.

What this does

A length converter changes a distance from one unit to another, metric units like millimeters, centimeters, meters, and kilometers, and imperial units like inches, feet, yards, miles, and nautical miles.

How to use it

  1. Enter a value and pick its unit.
  2. Choose the unit to convert to.
  3. Read the converted result instantly.
  4. Swap the units to reverse the conversion.

How it works

Every unit is defined against the meter, so each value is first converted to meters and then to the target unit. Because the inch is exactly 2.54 cm, metric–imperial length conversions are exact rather than rounded.

mm = inches × 25.4

Example

1 meter is about 3.281 feet, and 5 kilometers is about 3.107 miles. Going the other way, 12 inches is exactly 30.48 cm.

Sources & methodology

Last updated .

Frequently asked questions

Which length units are supported?

Millimeters, centimeters, meters, and kilometers on the metric side, plus inches, feet, yards, miles, and nautical miles.

How many centimeters are in an inch?

Exactly 2.54 cm. One inch is defined as 2.54 centimeters, so the conversion is exact rather than rounded.

Is my data stored?

No. Everything is calculated locally in your browser, nothing is uploaded or saved.