Length Converter
Instantly convert between mm, cm, m, km, inches, feet, yards and miles.
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 calculates mm, cm, m, km, inches, feet, yards and miles simultaneously. Just enter a value and all equivalents update instantly.
What Is a Length Converter and Why Is It Needed?
Even in countries where the metric system is dominant, you frequently encounter technical drawings, product catalogues, and e-commerce platforms that use inches and feet. Doing conversions by hand increases the risk of error; decimal mistakes in mm-to-inch conversions in particular require care.
The tool performs all calculations through metres: the entered value is first converted to metres, then to the target unit. This approach prevents chained rounding errors.
How to Use. 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_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) | — | 160,934 | 1.60934 | 63,360 | 5,280 | 1,760 | 1 |
Tips for Accurate Results
- When entering inches, use the decimal equivalent for fractional inches (e.g. 5½ inches = 5.5 in).
- A nautical mile differs from a statute mile; make sure you select the correct type for navigation tasks.
- Unit tolerance matters in technical drawings; for a dimension requiring ±0.5 mm precision, do not over-round the result.
- Cross-check the result against the unit specified in the original document; different standards may use the same abbreviation for different values.