How to convert units
Pick the quantity
Length, weight, area, temperature and more.
Type the value
Choose the unit to convert from and to. The swap button reverses them.
Read the result
The result and the conversion factor appear, with a table of the value in every unit below. Tap any unit to convert to it.
Common conversions (official values)
These factors are exact definitions, not approximations:
| From | Equals |
|---|---|
| 1 inch | 2.54 cm |
| 1 foot | 30.48 cm |
| 1 mile | 1.609344 km |
| 1 pound | 0.45359237 kg |
| 1 ounce | 28.349523125 g |
| 1 US gallon | 3.785411784 L |
| 1 UK gallon | 4.54609 L |
| 1 acre | 4,046.8564224 m² |
| Temperature | °F = °C × 9/5 + 32 |
| 1 kilocalorie | 4.184 kJ |
| 1 atmosphere | 101,325 Pa |
| 1 gigabyte (GB) | 1,000 megabytes |
| 1 gibibyte (GiB) | 1,024 mebibytes |
FAQ
How many centimeters are in an inch?
An inch is exactly 2.54 cm. So 10 inches = 25.4 cm, and 1 cm ≈ 0.3937 inches.
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. For example 100 °F = (100 − 32) × 5/9 ≈ 37.78 °C. The other way: multiply by 9/5 and add 32.
Why does my 1 TB drive show 931 GB?
Drives are sold in gigabytes (1000³ bytes) while Windows shows gibibytes (1024³ bytes) but labels them GB. 1,000 GB = 931.32 GiB; nothing is missing.
Is a US gallon the same as a UK gallon?
No. A US gallon is about 3.785 L and a UK (imperial) gallon about 4.546 L, so miles per gallon differ between them too.
What does ≈ mean?
The result is rounded to the digits chosen under “Precision”. = means it is exact, like 1 mile = 1.609344 km.