This imperial to metric conversion calculator converts temperature, length, area, volume, and weight between imperial and metric units.
Conversion
Imperial to Metric Conversion
Convert temperature, length, area, volume, and weight between imperial and metric units.
Calculator
About this calculator
Formula notes
Each quantity uses the exact captured definitions, such as 1 inch = 25.4 mm, 1 lb = 453.59237 g, and °F = 9/5 × °C + 32.
Worked examples
- Example: 1 inch is exactly 25.4 mm, and 100 °F is about 37.78 °C.
- One inch is exactly 25.4 millimeters, and 100 °F converts to about 37.78 °C.
How to use it
- Choose the conversion family (temperature, length, area, volume, or weight).
- Enter a value in the imperial field.
- Read the metric equivalents, or reverse the direction as needed.
Frequently asked questions
Are the conversions exact?
Yes for the defined relationships: the inch, pound, and gallon definitions are exact; temperature conversions follow the standard scale equations.
Which gallon does it use?
US and UK (imperial) gallons and their subunits are listed separately, so pick the field that matches your source.
Limits and interpretation
- The tool converts one family at a time (temperature, length, area, volume, or weight); US and UK volume units must be chosen deliberately.
- Extreme inputs or unit combinations that the captured definitions do not support will fail validation rather than approximate.