Free Unit Converter Online
Make sense of lengths, weights, and temperatures.
Convert measurements within the same category
A unit conversion expresses the same quantity on a different scale. Length and weight conversions multiply by a fixed factor; temperature conversions also adjust the zero point. Select the measurement category first so the source and target units are compatible. The tool accepts signed values for calculations but rejects temperatures below absolute zero.
How to use
- Choose length, weight or temperature.
- Enter your value and select the starting unit.
- Choose the destination unit and convert.
A few useful answers
Can I convert between weight and length?
No. These are different physical quantities. The unit lists only show units in your selected category.
Are negative numbers allowed?
Signed length and weight values are accepted for mathematical calculations. Temperature values must be at or above absolute zero.
How precise are the results?
Conversion factors use standard definitions, such as one inch being exactly 0.0254 metres. Results display up to 12 significant digits.