Universal Unit Converter
Convert length, mass, temperature, area, volume, speed, time, storage, pressure, energy, power and angle with clear formulas and adjustable precision.
Your data stays in your browser. No sign-in required.
Convert a measurement
Small and large numbers use scientific notation when needed. Trailing zeros are removed.
Converted result
1 Kilometre (km) =
Formula / conversion factor
1 km = 0.621371192237334 mi · result = input × 0.621371192237334
Quick conversions
Uses standard unit definitions and browser arithmetic. Live currency conversion is not included.
How to use this tool
- Choose a measurement category and the From and To units, or use a quick preset.
- Enter a decimal or scientific-notation value. Results update immediately; Swap units reverses the conversion direction.
- Choose 0–12 decimal places and copy the result. Very small or large values use scientific notation to avoid showing a misleading zero.
Privacy
Your entries and files are processed on your device. They are not uploaded, added to this page’s URL, saved in browser storage, or included in analytics. Reset clears this tool’s working state.
Frequently asked questions
Are US and Imperial units different?
Yes. Volume choices name the measurement system explicitly. US values use liquid measures and the customary cup. Horsepower is mechanical and calories are thermochemical.
How do kB and KiB differ?
kB, MB, GB and TB use powers of 1,000. KiB, MiB and GiB use powers of 1,024. All storage choices here measure bytes, not bits.
How precise are the results?
Conversions use standard constants and browser floating-point arithmetic, with approximately 15 significant digits. Display precision controls rounding; it cannot restore precision missing from the input. Temperatures below absolute zero and negative mass, volume, area, speed or storage are rejected. Live currencies are not included.