What is Length Converter?
Length Converter converts between all major metric and imperial length units simultaneously — from nanometers to miles. Enter a value in any unit and all others update in real time, so you always have the right measurement for your context.
All length unit conversions are exact — they use the international definitions agreed in 1959 (where 1 inch = 2.54 cm exactly).
Supported Length Units
Metric (SI)
nm, µm, mm, cm, m, km — the international standard used in science, most countries, and engineering.
Imperial / US
Inches, feet, yards, miles — used in the US and some UK contexts.
Nautical
Nautical miles — the standard unit for maritime and aviation distance measurement.
How to Use Length Converter
Enter a value
Type a length into any unit field — for example, enter 5 in the Feet field.
See all results
All other unit fields populate instantly. 5 feet = 1.524 m = 60 inches = 152.4 cm.
Copy any result
Click the copy icon next to the unit you need.
Quick Reference Conversion Table
| From | To | Multiply by |
|---|---|---|
| 1 inch | cm | 2.54 |
| 1 foot | meters | 0.3048 |
| 1 mile | km | 1.60934 |
| 1 km | miles | 0.62137 |
| 1 yard | meters | 0.9144 |
| 1 nautical mile | km | 1.852 |
Tips & Common Mistakes
Working with building plans? Architectural drawings in the US use feet and inches together (e.g. 5’9”). Convert feet separately, then add the inches conversion to get a total in cm or meters.
Don’t confuse UK and US measurements. The UK still uses miles for road distances but meters/centimeters for most other measurements — be explicit about which system a value uses.
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