Length
| From | To | Exact factor |
|---|---|---|
| 1 inch | centimetres | 2.54 |
| 1 foot | metres | 0.3048 |
| 1 yard | metres | 0.9144 |
| 1 mile | kilometres | 1.609344 |
Height example: 5 ft 8 in = 68 in × 2.54 = 172.72 cm.
Weight
| From | To | Factor |
|---|---|---|
| 1 pound | kilograms | 0.45359237 (exact) |
| 1 kilogram | pounds | about 2.2046 |
| 1 ounce | grams | about 28.35 |
| 1 stone | pounds | 14 |
Temperature
°C = (°F − 32) × 5 ÷ 9 | °F = °C × 9 ÷ 5 + 32
Body temperature of 98.6 °F is 37 °C. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea level. Quick estimate from °C to °F: double it and add 30.
Area and speed
| From | To | Factor |
|---|---|---|
| 1 square foot | square metres | 0.09290304 (exact) |
| 1 acre | square metres | 4,046.8564224 (exact) |
| 1 hectare | acres | about 2.471 |
| 1 mile per hour | km/h | 1.609344 (exact) |
| 1 knot | km/h | 1.852 (exact) |
Local land units, such as the marla, kanal or bigha, differ between regions and even between official records, so check the definition used in the document you are reading before converting.
Volume and data
- 1 US gallon = 3.785411784 litres; 1 imperial (UK) gallon = 4.54609 litres.
- Cups differ: a US customary cup is 236.588 mL and a metric cup is 250 mL. Recipes from different countries may mean different cups.
- Storage makers use decimal units: 1 GB = 1,000,000,000 bytes. Operating systems often show binary units: 1 GiB = 1,073,741,824 bytes. That is why a “1 TB” drive appears as about 931 GB on some computers.
Convert anything else
The Unit Converter covers ten categories, length, weight, temperature, area, volume, speed, data storage, time, pressure and energy. Choose a category, enter a value and its unit, and pick the target unit — or read the table, which shows the value in every unit of the category at once. Use Swap to reverse the direction. Conversions use exact international definitions.
For percentages and prices, see the percentage guide.
Frequently asked questions
Why do month conversions look approximate?
Months and years vary in length, so the converter uses average values (30.436875 and 365.2425 days). For exact calendar periods, use the Date Difference Calculator.
Is a ton the same everywhere?
No. A metric tonne is 1,000 kg, a US short ton is 2,000 lb (about 907 kg) and a UK long ton is 2,240 lb (about 1,016 kg).