Unit Converters
All six unit converters in one place. Switch between length, weight, temperature, speed, area, and volume. Results update instantly as you type.
New to converting between measurement systems? Read our guide explaining how unit conversion works to see when each converter is the right one to reach for.
Popular conversions, click to load:
Popular conversions, click to load:
Popular conversions, click to load:
Popular conversions, click to load:
Popular conversions, click to load:
Popular conversions, click to load:
Quick Reference
Best for: Converting length, weight, temperature, volume, area, speed, time and data units in one place without switching pages
Limitations: A general hub rather than a specialist calculator, so it does not handle currency or unusual scientific units
Best suited for: People who need occasional conversions across several unit types and want one bookmark
Frequently Asked Questions
How many cm in an inch?
1 inch = 2.54 centimetres exactly. This has been the internationally agreed definition since 1959. To convert inches to cm, multiply by 2.54. To convert cm to inches, divide by 2.54.
How many pounds in a kilogram?
1 kilogram = 2.20462 pounds. To convert kg to lbs, multiply by 2.20462. To convert lbs to kg, multiply by 0.453592.
How do I convert Celsius to Fahrenheit?
Multiply Celsius by 1.8 then add 32. Formula: F = C x 1.8 + 32. For example, 20°C = 20 x 1.8 + 32 = 68°F. To convert F to C: subtract 32, then divide by 1.8.
How many km/h in 1 knot?
1 knot = 1.852 km/h exactly. Knots are used in aviation and maritime navigation and are defined as one nautical mile per hour. 1 nautical mile = 1.852 km.
How many acres in a hectare?
1 hectare = 2.47105 acres. 1 acre = 0.404686 hectares. Hectares are the metric unit for land area (1 ha = 10, 000 m2). Acres are used primarily in the US, UK, and other countries that use the imperial system.
How many ml in a US cup?
1 US cup = 236.588 millilitres. 1 US tablespoon = 14.79 ml. 1 US teaspoon = 4.93 ml. Note that UK and Australian cups differ: 1 metric cup = 250 ml.
What This Section Covers
Six converters covering the measurements that most often need translating between metric and imperial: length, area, volume, weight, temperature and speed. Each works in both directions, converts through a single SI base unit so results stay exact, and explains the standards behind the units rather than only returning a number.
Reach for them when a document mixes systems. Property listings quoting square feet against square metres, recipes moving between Celsius and Fahrenheit or cups and millilitres, shipping priced by cubic metre against packaging labelled in inches, and speed limits posted in one unit while the vehicle displays the other. The temperature converter is the one that differs in kind, since those scales have different zero points as well as different degree sizes.