Unit Converter – length, weight, volume and temperature
Convert between metric and US units for length, weight, volume and temperature with instant results and sensible rounding.
How to use
- Choose a category: length, weight, volume or temperature.
- Type a value and pick the unit it is in and the unit you want.
- The result updates instantly, and the table below shows the same value in every unit of that category.
- Use Swap to reverse the direction.
About this tool
Length, weight and volume conversions go through a base unit (meter, gram, liter) using exact international definitions: an inch is 25.4 mm, a pound is 453.59237 g, and a US gallon is 3.785411784 liters. US customary cups, tablespoons and teaspoons use the standard 240 ml, 15 ml and 5 ml values found on nutrition labels; traditional US measures differ by a percent or two.
Temperature is not a simple multiple: Celsius to Fahrenheit is ×9/5 then +32, and Kelvin is Celsius plus 273.15. Results are rounded to a sensible number of significant figures. Everything runs in your browser.
FAQ
Which "ounce" does the weight category use?
The avoirdupois ounce, 28.349523125 g, which is the everyday ounce for food and body weight. Fluid ounces are a volume measure and live in the Volume category (US fluid ounce, 29.5735 ml).
Why is a US gallon different from a UK gallon?
They are different historical definitions. The US gallon is 3.785 liters; the imperial gallon is 4.546 liters. This tool includes both so you can convert between them.
How precise are the results?
Conversion factors are exact where a legal definition exists; display is rounded to about six significant figures, which is more than enough for cooking, shipping and everyday use.
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