Unit converter: length, weight, temperature, area and volume

How to use

1. Choose a quantity: length, weight, temperature, area or volume.
2. Enter a value and pick the units to convert from and to. The swap button reverses them.
3. The result appears instantly, together with a table of the value in every unit of that quantity.

Notes and limits

• Results show up to 10 significant digits with trailing zeros removed. Very large or small values are shown as "× 10ⁿ".
• Negative values are accepted for temperature only. Length, weight, area and volume must be 0 or more, and temperatures below absolute zero are rejected.
• Currency conversion is not included.
• The acre is the international acre (4,840 square yards), which differs very slightly from the US survey acre.

How it works

Length, weight, area and volume are converted through a base unit (m, kg, m², m³) using exact definitions: 1 in = 0.0254 m (1 ft = 12 in, 1 yd = 3 ft, 1 mi = 1,760 yd), 1 nautical mile = 1,852 m, 1 lb = 0.45359237 kg (1 oz = 1/16 lb, 1 st = 14 lb, short ton = 2,000 lb, long ton = 2,240 lb).

US gallon = 231 in³ (3.785411784 L) and imperial gallon = 4.54609 L. A US fluid ounce is 1/128 of a US gallon, an imperial fluid ounce is 1/160 of an imperial gallon, and each pint is 1/8 of its gallon. 1 tsubo = 400/121 m² (about 3.3058 m²).

Temperature is not proportional, so it is converted through kelvin: K = °C + 273.15 and °F = °C × 9/5 + 32.

Floating-point noise (such as 0.30000000000000004) is removed by rounding the display to 10 significant digits.