Unit Converter
Convert length, weight, temperature, area, volume, speed, time and digital storage — metric and imperial, both directions, instantly.
Everyday conversions, no rounding surprises
Whether you're following a recipe in the wrong units, sizing a parcel, reading a foreign weather report or working out a download, this converter handles the common categories in one place. It uses the exact defined factors, so the numbers match what an engineer or a standards table would give you.
How to use it
- Pick a category — length, weight, temperature and so on.
- Choose the units on each side, or hit swap to flip them.
- Type in either box. Enter a value on the left or the right and the opposite side updates as you type.
Frequently asked questions
Which units can I convert?
Eight categories: length (mm to miles), mass and weight (mg to stone), temperature (Celsius, Fahrenheit, Kelvin), area (mm² to square miles and acres), volume (ml to US gallons, cups and spoons), speed (m/s, km/h, mph, knots), time (ms to years) and digital storage (bits, bytes, KB/MB/GB and the binary KiB/MiB/GiB).
Does it convert both ways?
Yes. Type in either field and the other updates instantly, so you can go from metric to imperial or back without switching anything. The swap button flips the two units in place.
How accurate are the conversions?
Conversions use the exact internationally-defined factors (for example 1 inch = 0.0254 m exactly) and results are shown to about 10 significant figures, then trimmed of trailing zeros. Temperature uses the proper offset formulas rather than a simple ratio.
What's the difference between KB and KiB?
A kilobyte (KB) is 1,000 bytes, the decimal convention used for disk and network sizes. A kibibyte (KiB) is 1,024 bytes, the binary convention used by operating systems for memory. Both are included so you can convert between the two.