Temperature Converter
Convert Celsius, Fahrenheit, kelvin, Rankine, and Réaumur temperatures with formulas and copy-ready output.
Enter a temperature, choose the source and target scales, and generate a copy-ready conversion. The calculation stays in your browser and checks absolute zero so physically impossible temperatures are caught before results are shown.
Use a finite number. Commas as thousands separators and scientific notation are accepted.
How it works
The converter first expresses your input as kelvin, then derives the requested scale. Celsius and kelvin differ by an offset of 273.15, Fahrenheit uses 32 degrees at the freezing point of water with 180 intervals between freezing and boiling, and Rankine uses Fahrenheit-sized intervals from absolute zero.
Réaumur is included for reading historical recipes, brewing notes, and older scientific material. Its water freezing point is 0 °Ré and boiling point is 80 °Ré, so each degree Réaumur equals 1.25 degrees Celsius.
Use this tool for weather, cooking, lab-adjacent notes, HVAC estimates, classroom examples, and quick scale tables. It does not model measurement uncertainty, local calibration, or temperature-dependent material behavior.
