Length Converter
Convert between 12 length units, with the conversion factors shown so the result can be checked.
Your result will appear here as soon as you add some input.
How to use it
- 1Enter your values in the fields above.
- 2The answer and the working appear immediately below.
- 3Check the working to see the formula with your numbers substituted.
About the Length Converter
The inch has been defined as exactly 25.4 millimetres since the international yard and pound agreement of 1959, so every imperial length here converts exactly rather than approximately.
The nautical mile is the odd one out: it is exactly 1,852 metres, chosen because it is close to one minute of latitude, which is why it is still used at sea and in the air.
Every unit converts through a single base unit, so the arithmetic is one multiplication and one division - both shown in the working, along with the exact factor used.
Questions people ask
Is your figures uploaded to a server?
No. This tool runs entirely in your browser using standard web APIs, so your figures never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.
Is it free, and do I need an account?
Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.