Unit Converter: Length, Weight & Temperature

Popular conversions

mi → km km → mi ft → m m → ft in → cm cm → in yd → m °C → °F °F → °C °C → K K → °C kg → lb lb → kg oz → g g → oz st → kg L → US gal US gal → L mL → US fl oz km/h → mph mph → km/h kn → km/h m² → ft² ft² → m² ac → ha kcal → kJ kJ → kcal BTU → kJ psi → bar bar → psi atm → Pa

All unit categories

Shoe and clothing sizes are in the converter above under Sizing.

Frequently asked questions

How accurate are the conversions?

Factors are the exact legal definitions where one exists (1 inch = 2.54 cm, 1 pound = 0.45359237 kg, 1 US gallon = 3.785411784 L) and otherwise the values published by NIST and the BIPM. Each category page lists its sources. Results are shown to 10 significant digits.

Can I convert between metric and imperial?

Yes. Imperial and US customary units have been defined exactly in metric units since 1959, so converting between them is exact. Volumes use US customary measures; UK (imperial) gallons and pints are larger.

Why can't I convert amps to volts or cups to grams?

Those are different physical quantities. Amps to volts needs a resistance (Ohm's law), and cups to grams needs the ingredient's density. The converter only offers conversions between units of the same quantity.