Réaumur to Delisle Conversion Calculator: Free Online Tool
Convert degrees Réaumur to degrees Delisle with our free online temperature converter.
Réaumur to Delisle Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Réaumur).
- The converted value in Delisle will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Temperature category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Réaumur to Delisle
Temperature conversions like Réaumur to Delisle use specific non-linear formulas.
Formula:
First convert °Ré to °C: °C = °Ré × 5/4. Then convert °C to °De: °De = (100 - °C) × 3/2Example Calculation:
Convert 10°Ré:
1. °C = 10 × 5/4 = 12.50°C
2. °De = (100 - 12.50) × 3/2 = 131.3°De
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Réaumur and a Delisle?
The Réaumur scale (°Ré, °Re, °R) is a temperature scale where the freezing point of water is 0 degrees and the boiling point is 80 degrees.
The Delisle scale (°De) is a historical temperature scale where the boiling point of water is set at 0 degrees and the freezing point at 150 degrees. The scale decreases as thermal energy increases.
Note: The Réaumur is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Delisle belongs to the imperial/US customary system.
History of the Réaumur and Delisle
Developed by René Antoine Ferchault de Réaumur in 1730, it was based on the expansion of alcohol. He marked the freezing point as 0 and the boiling point of the alcohol solution as 80. It gained popularity in parts of Europe, particularly France and Germany, but has largely been replaced by Celsius.
Invented by the French astronomer Joseph-Nicolas Delisle in 1732 for use in Russia. He defined his scale with the boiling point of water as 0 °De and the freezing point as 150 °De. It was used primarily in Russia for about a century.
Common Uses for degrees Réaumur and degrees Delisle
Explore the typical applications for both Réaumur (imperial/US) and Delisle (imperial/US) to understand their common contexts.
Common Uses for degrees Réaumur
- Historical Context: Found in old scientific literature and historical documents.
- Specific Industries: Occasionally used in some specific contexts, such as cheesemaking in Italy (for Parmigiano-Reggiano) or for measuring sugar syrup temperature in some Dutch cooking.
Common Uses for degrees Delisle
- Historical Significance: Of interest in the history of thermometry, particularly in Russia.
- Not used in modern scientific or general applications.
Frequently Asked Questions
Questions About Réaumur (°Ré)
What are the freezing and boiling points of water in Réaumur?
Water freezes at 0 °Ré and boils at 80 °Ré.
How does Réaumur relate to Celsius?
The Réaumur degree is larger than the Celsius degree. The formula is °Ré = °C × 4/5.
Is the Réaumur scale still commonly used?
No, it is rarely used today, having been largely superseded by the Celsius scale.
About Delisle (°De)
What are the freezing and boiling points of water in Delisle?
Water boils at 0 °De and freezes at 150 °De. Note that the scale is inverted compared to Celsius or Fahrenheit.
Why does the Delisle scale decrease with increasing temperature?
Delisle set the boiling point of water as his zero reference and measured the contraction of mercury as it cooled, leading to higher numbers for colder temperatures.
How does Delisle relate to Celsius?
The relationship is °De = (100 - °C) × 3/2.