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Universal Unit Converter
Unit Converter converts between the units people actually use: length (metres, kilometres, centimetres, feet, inches), weight, temperature (Celsius, Fahrenheit, Kelvin) and speed. The result updates as you type, so you can compare units without pressing a button.
How to use Universal Unit Converter
- Choose the measurement category.
- Enter the value and pick the unit you are converting from and to.
- Read the converted figure, which updates live, and copy it if you need it.
Where Universal Unit Converter is useful
- Converting a recipe or a spec sheet between metric and imperial.
- Reading a temperature forecast in the scale you think in.
- Checking a running or cycling pace in different units.
- Sanity-checking a dimension before ordering materials.
Formats, algorithms and limits
Length and weight convert by fixed ratios; temperature uses the offset formulas, which is why 0 in Celsius is not 0 in Fahrenheit. Results are shown to four decimal places and trimmed, so a whole number result reads as a whole number rather than as a row of zeros.
Troubleshooting and honest limits
- Check the category first: the unit lists change with it, and picking the wrong pair is the usual source of a surprising answer.
- For temperature, remember the intervals differ as well as the zero points — 20 Celsius is 68 Fahrenheit, not 52.
- Keep trailing units in your own notes; the converted number is meaningless without knowing which unit it is in.
Frequently asked questions
Which categories are available?
Length, weight, temperature and speed cover the common conversions. Currency is deliberately not here because exchange rates change daily — the dedicated currency converter handles that with its own rate note.
Why does the value change as I type?
Conversion runs on every keystroke, so you can type a number and watch the counterpart unit update without submitting a form.
How precise are the results?
The underlying factors are the standard exact definitions, and the display keeps four decimal places, which is more than enough for everyday work.
Does it work offline?
Yes, all the factors are built into the page, so conversion works with no connection.
Related tools
Page written and reviewed by the FreeConvertio engineering team on 2026-10-14. Universal Unit Converter runs entirely in your browser — no uploads, no account and no daily limits.