Unit Converter

Multiply by 9/5 (1.8) and add 32. For example, 20 °C × 1.8 + 32 = 68 °F. To go back, subtract 32 and multiply by 5/9: 68 °F is (68 − 32) × 5/9 = 20 °C.

Exactly 2.54. The inch has been defined as 25.4 mm since 1959, so 12 inches (a foot) is 30.48 cm.

They come from different historical standards. A US gallon is 3.785 litres and a UK (imperial) gallon is 4.546 litres, about 20% larger. The same applies to pints and fluid ounces, so check which one a recipe or fuel figure uses.

Drive makers use decimal units (1 TB = 1,000,000,000,000 bytes), but Windows reports sizes in binary units of 1,024. 10¹² bytes ÷ 1,024³ is about 931 GiB, which Windows labels “GB”.

Divide 235.215 by the L/100 km figure for US mpg, or 282.481 for UK mpg. 8 L/100 km is about 29.4 mpg (US) or 35.3 mpg (UK). Because one is fuel per distance and the other distance per fuel, a lower L/100 km is better but a higher mpg is better.

They use the exact legal definitions where one exists, such as 1 lb = 0.45359237 kg, and show up to 10 significant figures. Very large or small results are shown in scientific notation.

1 kg is 2.204622622 lb, because a pound is defined as exactly 0.45359237 kg. So 70 kg is 154.3235835 lb, or 11.02311311 stone. A quick estimate is to double the kilograms and add 10%.

Divide by 1.609344, the number of kilometers in a mile. 100 km/h is 62.13711922 mph, and 60 mph is 96.56064 km/h. To get meters per second, divide km/h by 3.6.

A tonne (metric ton) is 1,000 kg. A US short ton is 2,000 lb, or 907.18474 kg, and a UK long ton is 2,240 lb, or 1,016.046909 kg. The converter lists all three separately so you can pick the right one.

Kelvin is the scientific temperature scale that starts at absolute zero, the coldest possible temperature: K = °C + 273.15, so 20 °C is 293.15 K. Celsius and Fahrenheit go below zero, but nothing goes below 0 K (−273.15 °C or −459.67 °F), and the converter warns if you enter a lower value.

Yes. Thousands separators like 1,250.5 and Indian-style grouping like 1,25,000 both work, a single comma as a decimal point like 12,5 is read as 12.5, and you can enter scientific notation such as 1e-3.

No. Conversions run in your browser and nothing is saved or uploaded.