Unit Converter
Pick a category, enter a number and see it converted into every unit at once.
How the converter works
Every unit is first converted to a base unit (meters, grams, square meters, liters, meters per second or bytes) using its exact definition, then converted back out to every other unit. Temperature is the exception: Fahrenheit, Celsius and Kelvin have different zero points, so they use formulas rather than a single factor.
Handy conversions to remember
| Unit | Equals | Rule of thumb |
|---|---|---|
| 1 inch | 2.54 cm | Exact by definition |
| 1 mile | 1.609 km | Multiply by 8, divide by 5 |
| 1 pound (lb) | 0.4536 kg | Divide by 2.2 |
| 1 stone | 6.35 kg | 14 lb |
| 1 acre | 4,046.9 m² | About 0.4 hectares |
| 1 US gallon | 3.785 L | UK gallon is 4.546 L |
| °F to °C | (°F - 32) x 5/9 | Subtract 30, halve it |
Looking for more everyday tools? See our life tools or all calculators.
Frequently asked questions
How many centimeters are in an inch?
One inch is exactly 2.54 cm, and one foot (12 inches) is exactly 30.48 cm. Screen sizes are measured along the diagonal, so a 27-inch monitor is about 68.6 cm corner to corner.
How do I convert pounds to kilograms?
One pound is exactly 0.45359237 kg, so divide pounds by about 2.2046 to get kilograms. A stone, used for body weight in the UK and Ireland, is 14 pounds or about 6.35 kg.
Why are US and UK gallons different?
They come from different historical standards. A US gallon is 3.785 liters, while an imperial (UK) gallon is 4.546 liters, about 20% larger. US and UK fluid ounces and pints differ too, so pick the right one when following a recipe or comparing fuel economy.
Is 1 GB equal to 1,000 MB or 1,024 MB?
Both are used. The international (SI) standard is 1 GB = 1,000 MB, which storage makers use on the box. Windows and some apps count in binary, where 1 GB = 1,024 MB (strictly a GiB). That is why a 1 TB drive shows up as about 931 GB in Windows. You can switch between the two here.