Length Converter
Convert between mm, cm, m, km, inches, feet, yards and miles.
This tool is for information only. Results are rounded for display; for technical dimensions that need precision such as ±0.5 mm, check the result against the unit in the source document.
Length Converter: Metres, Inches, Feet and Miles in One Place
International technical documents use metric and imperial (British-American) units side by side. The length converter shows the value you enter in mm, cm, m, km, inches, feet, yards and miles at once.
What Is a Length Converter and Why Is It Needed?
Even where the metric system dominates, you often come across technical drawings, product catalogues and online shops that use inches and feet. Converting by hand raises the risk of mistakes; watch the decimals especially when converting between mm and inches.
The tool runs every calculation through metres: the value is converted to metres first, then to the target unit. This avoids chained rounding errors.
How to Use It, Step by Step
Required Inputs
- The numeric value you want to convert
- Source unit (mm / cm / m / km / in / ft / yd / mi)
Formula / Calculation Logic
Metres = Input × Metre factor. Result = Metres ÷ Target unit's metre factor. Example: 72 inches → m: 72 × 0.0254 = 1.8288 m. Or: 5 feet → cm: 5 × 0.3048 × 100 = 152.4 cm.
Conversion Factors Table
| Unit | mm | cm | km | in | ft | yd | mi |
|---|---|---|---|---|---|---|---|
| 1 Metre (m) | 1,000 | 100 | 0.001 | 39.3701 | 3.2808 | 1.0936 | 0.000621 |
| 1 Centimetre (cm) | 10 | 1 | 0.00001 | 0.3937 | 0.03281 | 0.01094 | — |
| 1 Kilometre (km) | 1,000,000 | 100,000 | 1 | 39,370 | 3,280.8 | 1,093.6 | 0.62137 |
| 1 Inch (in) | 25.4 | 2.54 | — | 1 | 0.08333 | 0.02778 | — |
| 1 Foot (ft) | 304.8 | 30.48 | 0.000305 | 12 | 1 | 0.33333 | 0.000189 |
| 1 Yard (yd) | 914.4 | 91.44 | 0.000914 | 36 | 3 | 1 | 0.000568 |
| 1 Mile (mi) | 1,609,344 | 160,934.4 | 1.609344 | 63,360 | 5,280 | 1,760 | 1 |
Tips for Accurate Results
- Enter fractional inches as decimals (e.g. 5½ inches = 5.5 in).
- A nautical mile is not the same as a statute mile; make sure you use the right one for navigation.
- Tolerances matter in technical drawings; for a dimension that needs ±0.5 mm precision, don't over-round the result.
- Check the result against the unit in the original document; different standards can use the same abbreviation for different values.