Réaumur Converter
Convert temperatures between the historical Réaumur scale and Celsius, Fahrenheit and Kelvin — useful for old recipes, cheese making and historical texts.
How to use the Réaumur Converter
- Enter the temperature.
- Choose the scale it is in.
- Read the equivalent values.
How it works
The Réaumur scale, introduced by René Antoine Ferchault de Réaumur in 1730, puts the freezing point of water at 0 °Ré and the boiling point at 80 °Ré. So °Ré = °C × 4/5 and °C = °Ré × 5/4; for Fahrenheit, °F = °Ré × 9/4 + 32. It remained common in parts of Europe into the 20th century and is still seen in Italian and Swiss cheese making and old candy recipes.
Réaumur conversion table
| °Ré | °C | °F |
|---|---|---|
| -20 | -25 | -13 |
| 0 | 0 | 32 |
| 10 | 12.5 | 54.5 |
| 16 | 20 | 68 |
| 20 | 25 | 77 |
| 30 | 37.5 | 99.5 |
| 37 | 46.25 | 115.25 |
| 40 | 50 | 122 |
| 60 | 75 | 167 |
| 80 | 100 | 212 |
Frequently asked questions
What is 80 °Ré in Celsius?
100 °C — the boiling point of water.
How do I convert Réaumur to Fahrenheit?
Multiply by 9/4 and add 32: 20 °Ré = 77 °F.
Is Réaumur still used?
Rarely — mainly in traditional cheese making in Italy and Switzerland and in historical documents.
What is absolute zero in Réaumur?
−218.52 °Ré.