°Ré to °C Converter – Convert Réaumur to Celsius

Temperature conversions are affine, not multiplicative: the formula °C = °Ré × 1.25 both shifts the zero point and rescales the interval. Worked example: 10 °Ré becomes 12.5 °C. Celsius, Fahrenheit, Kelvin and Réaumur measure the same temperatures on shifted and stretched scales, so converting between them is never a single multiplication: an offset must be added or removed as well. The formulas are exact definitions of the scales themselves, so results are limited only by the decimals you carry — two decimals match every laboratory and weather use. The reverse direction applies °Ré = °C × 0.8, so 12.5 °C returns 10 °Ré. Mini conversion table: 1 °Ré = 1.25 °C; 5 °Ré = 6.25 °C; 10 °Ré = 12.5 °C; 50 °Ré = 62.5 °C; 100 °Ré = 125 °C. Anchor points make the direction obvious: water freezes at 0 °C = 32 °F = 273.15 K and body temperature is about 37 °C = 98.6 °F; if your result disagrees with those, the offset term was dropped.

1. 1

   Step 1

   Enter your value in Réaumur (°Ré)

2. 2

   Step 2

   The tool applies the formula °C = °Ré × 1.25 in one step

3. 3

   Step 3

   Read the result in Celsius (°C)

4. 4

   Step 4

   Hit swap to convert Celsius back to Réaumur instantly

• 1

  Memorize the pair −40 °C = −40 °F, the one point where both scales meet

• 2

  Ovens: 180 °C ≈ 350 °F and 200 °C ≈ 400 °F cover most baking

• 3

  Kelvin never goes negative — a minus sign means an input error

• 4

  Weather shorthand: °F ≈ °C × 2 + 30 is close enough for packing decisions

• Saying "1 °C = 33.8 °F" — ratios never work between temperature scales, only the affine formula does

• Forgetting the +32 (or −32) offset term when switching direction

• Mixing °C increments with K values in gas-law formulas — K has no degree sign