Quick unit conversion chart
| Convert | Formula |
|---|---|
| Inches to centimeters | in × 2.54 |
| Centimeters to inches | cm ÷ 2.54 |
| Pounds to kilograms | lb × 0.45359237 |
| Kilograms to pounds | kg × 2.20462262 |
| Fahrenheit to Celsius | (°F − 32) × 5/9 |
| Celsius to Fahrenheit | °C × 9/5 + 32 |
| Miles per hour to km/h | mph × 1.609344 |
| kWh to joules | kWh × 3,600,000 |
Length example: inches to centimeters
Multiply inches by 2.54. For example, 10 inches × 2.54 = 25.4 centimeters. Use the inches to cm calculator or cm to inches calculator for quick conversions.
Weight example: pounds to kilograms
Multiply pounds by 0.45359237. A 150 lb value is approximately 68.04 kg.
Temperature conversions
Temperature is different from simple scale-factor conversions because Fahrenheit and Celsius have different zero points. Use Fahrenheit to Celsius or Celsius to Fahrenheit.
Speed and pace
Speed can be converted directly, while running pace is time per unit of distance. See the MPH to pace conversion guide.
Energy conversions
Use the energy converter for joules, kilojoules, calories, kilocalories, watt-hours and kilowatt-hours.
Frequently asked questions
Why do some conversion formulas multiply while others add or subtract?
Most units differ by a scale factor, but temperature scales also use different zero points.