Unit Converter
Convert between all common units for length, area, volume, mass and temperature. Enter any value and all others update.
About unit conversions
Metric units (mm, cm, m, km) and imperial/US units (inch, foot, yard, mile). 1 inch = 25.4 mm exactly.
Includes hectare and acre for land measurement. 1 hectare = 10,000 m². 1 acre = 4,047 m².
Covers culinary (tsp, tbsp, cup), UK/US pints, and SI units. Note: US and UK cups differ slightly.
From milligrams to tonnes. 1 pound = 453.592 g. 1 troy ounce (gold) = 31.1035 g (not shown — use the avoirdupois ounce here).
°C, °F, and Kelvin. Uses exact formulas (not ratio). Water freezes at 0°C = 32°F = 273.15 K.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 cm. This is the international definition. So 1 foot (12 inches) = 30.48 cm, and 1 metre = 39.3701 inches.
What is the difference between a US gallon and a UK gallon?
A US gallon = 3.785 litres. A UK (imperial) gallon = 4.546 litres. This calculator uses US gallons for the gallon field, which is standard for fuel economy in the US.
How do you convert Celsius to Fahrenheit?
Use the formula: °F = (°C × 9/5) + 32. For example, 100°C (boiling water) = 212°F. To convert back: °C = (°F − 32) × 5/9.
What is a hectare in acres?
1 hectare = 2.47105 acres. In Indian land measurement, you may also encounter bigha, gunta, and cent — these vary by state and are not in this converter.
How many teaspoons in a tablespoon?
3 teaspoons = 1 tablespoon. In the metric system, 1 tsp = 5 ml and 1 tbsp = 15 ml. A US cup = 240 ml (16 tablespoons).