What Does the Unit Converter Do?
This converter translates measurements across four everyday categories — length, weight/mass, temperature and speed — spanning metric and imperial systems. Enter a value, choose "from" and "to" units, and the answer appears live, together with a table converting your value into every other unit in the category at once. A swap button flips the direction instantly.
Conversions use exact internationally defined factors (an inch is exactly 25.4 mm, a pound exactly 0.45359237 kg), so results are precise, with very large and very small numbers shown in scientific notation for readability.
How to Convert Units
- Pick the category: length, weight, temperature or speed.
- Enter your value and select the source unit.
- Choose the target unit — or just read the all-units table below the result.
- Use ⇄ to swap direction.
Coverage
- Length — mm, cm, m, km, inches, feet, yards, miles, nautical miles.
- Weight — mg, g, kg, metric tonnes, ounces, pounds, stones, US tons.
- Temperature — Celsius, Fahrenheit, Kelvin (formula-based, not simple factors).
- Speed — m/s, km/h, mph, ft/s, knots.
Handy anchors to remember: 1 inch = 2.54 cm, 1 kg ≈ 2.2 lb, 1 mile ≈ 1.6 km, 100 km/h ≈ 62 mph, and 1 knot = 1 nautical mile per hour ≈ 1.85 km/h.