About the Length Converter
The Length Converter turns any length into every other common unit in one glance. Type in centimeters and see feet, meters, yards, kilometers, and miles update at the same time. There is no "convert" button — every field is both an input and an output, so any change ripples through the rest instantly.
Nothing you type is sent anywhere. All arithmetic runs in your browser, so the page keeps working offline once it loads.
Common uses
- Height — enter 170 cm to see 5′ 6.9″ (feet + inches).
- Furniture & TV sizing — a 55″ TV is 139.7 cm on the diagonal.
- Travel distances — a marathon is 42.195 km / 26.219 miles.
- Print & design — DIN A4 is 21 cm × 29.7 cm / 8.27″ × 11.69″.
- Rulers & DIY — quickly go between mm precision and inches with fractions.
Which units are supported?
Metric: millimeter (mm), centimeter (cm), meter (m), kilometer (km).
Imperial & US: inch (in), foot (ft), yard (yd), mile (mi).
Combined: feet + inches (for human height and everyday measurements), plus nautical mile (for aviation, sailing, and maritime distances). One nautical mile is defined as 1852 meters exactly.
Precision
Every unit is rounded to 6 significant digits with trailing zeros stripped — enough for engineering use, without the false precision of ten-decimal floating-point noise. The feet+inches row shows inches to 2 decimals, since anything past that is meaningless when you're using a physical ruler.
Privacy
All conversion runs client-side in JavaScript. Your inputs never leave the browser.