How to use the unit converter
- Pick a category: length, weight, temperature, area, volume or speed.
- Type a value and choose the units to convert from and to.
- The result appears instantly, and the table below shows the value in every other unit as well.
Common conversions
| Conversion | Multiply by |
|---|---|
| Inches → centimetres | 2.54 |
| Feet → metres | 0.3048 |
| Miles → kilometres | 1.609344 |
| Pounds → kilograms | 0.45359237 |
| Ounces → grams | 28.3495 |
| US gallons → litres | 3.78541 |
| Miles/hour → km/hour | 1.609344 |
| Square feet → square metres | 0.092903 |
Temperature formulas
°F = °C × 9/5 + 32
°C = (°F − 32) × 5/9
K = °C + 273.15
Handy reference points: water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F). Normal body temperature is about 37 °C (98.6 °F).
Metric vs. imperial
Most of the world uses the metric system, which is based on powers of ten. The United States still uses US customary units for everyday measurements, and the UK uses a mix of both. That's why converting between them comes up so often in recipes, travel, shopping and school work.
Frequently asked questions
How many centimetres are in an inch?
One inch is exactly 2.54 centimetres. To convert inches to cm, multiply by 2.54; to convert cm to inches, divide by 2.54.
How do I convert kg to pounds?
Multiply kilograms by 2.20462. For example, 70 kg is about 154.3 lb. To go from pounds to kilograms, multiply by 0.453592.
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. So 25 °C is 25 × 1.8 + 32 = 77 °F. To go back, subtract 32 and multiply by 5/9.
Are US and UK gallons the same?
No. A US gallon is 3.785 litres and a UK (imperial) gallon is 4.546 litres. This converter lists both separately.