Common conversion factors
| From | To | Multiply by |
|---|---|---|
| Inch | Centimetre | 2.54 |
| Foot | Metre | 0.3048 |
| Mile | Kilometre | 1.609344 |
| Pound | Kilogram | 0.45359237 |
| Ounce | Gram | 28.349523 |
| US gallon | Litre | 3.785412 |
Converting temperature
Temperature is unlike other units: multiplying by a factor is not enough, because the scales have different zero points.
°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
K = °C + 273.15
°C = (°F − 32) × 5/9
K = °C + 273.15
Example: 25°C = (25 × 1.8) + 32 = 77°F.
Frequently asked questions
How many centimetres are in an inch?
One inch is exactly 2.54 centimetres. This is an official definition, not an approximation.
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 (that is 1.8) and add 32. So 25°C equals 77°F.
How many kilograms are in a pound?
One pound equals 0.45359237 kilograms, roughly 0.454 kg.
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