Convert réaumur to celsius with confidence
1 °Ré x 1.25 = 1.25 °C
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Imagine finding an 18th-century French recipe that calls for baking at 40°Ré. Would you know your oven temperature? That's where understanding réaumur to celsius conversion becomes more than just math—it's a bridge between historical knowledge and modern practicality. While most of us grew up with Celsius and Fahrenheit, the Réaumur scale whispers stories from the Age of Enlightenment, when scientists first systematically explored temperature measurement.
Unit definitions
What is a réaumur (°ré)?
- Description: Historical temperature scale created by French scientist René Antoine Ferchault de Réaumur
- Symbol: °Ré
- Common uses: 18th-19th century European science, some traditional cheese production
- Definition: Water freezes at 0°Ré and boils at 80°Ré under standard atmospheric pressure
What is a celsius (°c)?
- Description: Modern metric temperature scale used worldwide (except in few countries)
- Symbol: °C
- Common uses: Weather reports, cooking, scientific research
- Definition: Water freezes at 0°C and boils at 100°C at sea level
Conversion formula
The straightforward conversion formula: celsius = réaumur × 1.25
Let's break this down. Since Réaumur divides the fundamental interval (freezing to boiling) into 80 degrees while Celsius uses 100, each Réaumur degree equals 1.25 Celsius degrees. To convert:
- Take your Réaumur temperature
- Multiply by 1.25
- Result is Celsius equivalent
Example calculations
Example 1: Convert 20°Ré to Celsius
20 × 1.25 = 25°C
(Perfect room temperature in Celsius terms)
Example 2: Convert 60°Ré to Celsius
60 × 1.25 = 75°C
(Ideal for pasteurizing milk, coincidentally)
Conversion tables
Réaumur to celsius
| Réaumur (°Ré) | Celsius (°C) |
|---|---|
| 0 | 0.00 |
| 10 | 12.50 |
| 20 | 25.00 |
| 30 | 37.50 |
| 40 | 50.00 |
| 50 | 62.50 |
| 60 | 75.00 |
| 70 | 87.50 |
| 80 | 100.00 |
Celsius to réaumur
| Celsius (°C) | Réaumur (°Ré) |
|---|---|
| 0 | 0.00 |
| 10 | 8.00 |
| 20 | 16.00 |
| 30 | 24.00 |
| 40 | 32.00 |
| 50 | 40.00 |
| 60 | 48.00 |
| 70 | 56.00 |
| 80 | 64.00 |
| 90 | 72.00 |
| 100 | 80.00 |
Historical context
The Réaumur scale first appeared in 1730, developed through experiments with alcohol thermometers. Its creator, René Réaumur, was actually better known for his work in entomology—proof that scientific curiosity often crosses discipline boundaries. The scale gained popularity in Europe, particularly in France and Germany, where it remained in use until the late 1800s.
Interestingly, Russia's Dmitri Mendeleev (of periodic table fame) used Réaumur measurements in early chemistry experiments. The scale's decline began when metric system adoption accelerated in teh 20th century, though you'll still find vintage thermometers marked with °Ré in antique shops across Europe.
Interesting facts...
- Cheese connection: Traditional Swiss Gruyère production still references Réaumur in aging processes
- Literary cameo: Tolstoy mentions Réaumur temperatures in War and Peace
- Scale siblings: Réaumur's 80-degree system inspired the 80-proof alcohol measurement
- Kitchen survivor: Some French baking books printed before 1950 use Réaumur for oven temps
- Cold calculation: -40°Ré equals -40°C—the only temperature where two scales align
FAQ
While mostly obsolete, it occasionally appears in European cheese production recipes or historical document references.
Conversions are useful for interpreting old scientific data, cooking vintage recipes, or understanding historical weather records.
Yes, the linear relationship (Celsius = Réaumur × 1.25) works consistently across the scale's range.
Fahrenheit uses different reference points. To convert Réaumur to Fahrenheit: °F = °Ré × 2.25 + 32.
No nation fully adopted it, but it was widely used in 19th-century European science and industry.