Celsius to Réaumur Formula
To convert Celsius (°C) to Réaumur (°Ré), use the following formula:
°Ré = °C × 4/5
The formula keeps full precision during the calculation and rounds only the displayed result when needed. For example, 25 °C converts to 20 °Ré.
Key Temperature References
| Celsius (°C) | Réaumur (°Ré) | Reference |
|---|
| 0 °C | 0 °Ré | Freezing point of water |
| 20 °C | 16 °Ré | Room temperature |
| 37 °C | 29.6 °Ré | Average body temperature |
| 100 °C | 80 °Ré | Boiling point of water |
How to Convert Celsius to Réaumur (°C to °Ré)
Follow these simple steps:
- Take the temperature in Celsius. Example: 25 °C
- Apply the formula °Ré = °C × 4/5.
- The result is 25 °C = 20 °Ré.
Another Quick Example
| 0 °C | → | 0 °Ré |
| 20 °C | → | 16 °Ré |
| 30 °C | → | 24 °Ré |
| 40 °C | → | 32 °Ré |
For instant conversions, use the converter above to calculate temperatures automatically with full accuracy.
Common Celsius to Réaumur Conversions
The table below shows frequently searched conversions, grouped by use case.
| Celsius (°C) | Réaumur (°Ré) | What It Feels Like |
|---|
| 🌨️ Cold & Freezing |
| -40 °C | -32 °Ré | Extreme Cold |
| -20 °C | -16 °Ré | Very Cold |
| -10 °C | -8 °Ré | Below Freezing |
| 0 °C | 0 °Ré | Freezing Point |
| 🌤️ Cool & Mild Weather |
| 5 °C | 4 °Ré | Cold Morning |
| 10 °C | 8 °Ré | Cool |
| 15 °C | 12 °Ré | Mild |
| 20 °C | 16 °Ré | Room Temperature |
| ☀️ Warm & Hot Weather |
| 25 °C | 20 °Ré | Warm Day |
| 30 °C | 24 °Ré | Hot Summer Day |
| 35 °C | 28 °Ré | Very Hot |
| 40 °C | 32 °Ré | Extreme Heat |
| 🩺 Body Temperature |
| 37 °C | 29.6 °Ré | Normal Body Temperature |
| 38 °C | 30.4 °Ré | Low-Grade Fever |
| 39 °C | 31.2 °Ré | Fever |
| 40 °C | 32 °Ré | High Fever |
| 🍳 Cooking Temperatures |
| 50 °C | 40 °Ré | Very Warm / Poaching |
| 75 °C | 60 °Ré | Hot Liquid / Steep |
| 100 °C | 80 °Ré | Boiling Point |
Quick Celsius to Réaumur Conversion
The Celsius to Réaumur converter helps quickly convert values into the Réaumur scale.
0 °C=0 °Ré
20 °C=16 °Ré
25 °C=20 °Ré
37 °C=29.6 °Ré
100 °C=80 °Ré
Practical Uses
This conversion tool is widely used across several sectors, including:
🌤️Weather Forecasting & Meteorology — Essential for analyzing global climate patterns, converting international satellite data, and presenting regional weather reports across different standard metrics.
🍳Cooking, Baking & Culinary Arts — A vital tool for chefs and home cooks adjusting oven temperatures, candy-making thresholds, or sous-vide settings when working with foreign cookbooks and international recipes.
🔬Scientific Research & Laboratories — Used by researchers and students to seamlessly convert data during chemical reactions, thermodynamic studies, and physical state experiments that require strict adherence to global scientific standards.
🩺Medical & Healthcare Readings — Helps medical professionals accurately evaluate patient charts, monitor body temperature fluctuations, and safely administer treatments when dealing with medical equipment or documentation from different regions.
🏗️HVAC & Building Engineering — Crucial for heating, ventilation, and air conditioning technicians calculating thermal loads, configuring smart thermostats, and installing climate control systems with varying manufacturer specs.
🏭Manufacturing & Industrial Processes — Vital for monitoring machinery operating limits, managing heat-treatment cycles, and ensuring product quality control across global supply chains.
✈️International Travel & Aviation — Ideal for global travelers, pilots, and logistics managers adjusting to local climate reports, checking baggage storage requirements, or planning activities based on regional temperature standards.
Understanding Celsius and Réaumur
Celsius (°C) and Réaumur (°Ré) are temperature scales used in different regions and fields. While both measure temperature, they use different reference points.
What Is Celsius (°C)?
Celsius is the standard temperature scale used in most countries and is part of the metric system.
Why Celsius is popular
- Water freezes at 0°C
- Water boils at 100°C
- Widely used in weather forecasts, education, and scientific research
- Official temperature scale in most countries worldwide
Because it is based on simple, easy-to-understand reference points, Celsius is commonly used for everyday temperature measurements.
What Is Réaumur (°Ré)?
Réaumur is a historical temperature scale that sets the freezing and boiling points of water at 0 and 80 degrees.
About Réaumur
- Water freezes at 0 °Ré
- Water boils at 80 °Ré
- Historically used across Europe, especially in the food industry
- Rarely used today
Réaumur is mostly of historical interest but still appears in some traditional recipes and older scientific texts.
Celsius vs Réaumur: Key Differences
| Feature | Celsius (°C) | Réaumur (°Ré) |
|---|
| Water Freezes | 0°C | 0 °Ré |
| Water Boils | 100°C | 80 °Ré |
| Primary Usage | Most countries | Historical (Europe) |
| Scientific Use | Standard scale | Rarely used |
| Weather Forecasts | Global standard | Not used |
When Do You Need to Convert Between Them?
Converting Celsius to Réaumur is useful when:
- Checking weather forecasts from another country
- Following international cooking recipes
- Reading scientific or educational materials
- Traveling between regions that use different temperature scales
- Comparing body temperature readings from different sources
Quick Reference: Common Temperature Points
Familiar reference points across the Celsius and Réaumur scales.
| Reference | Celsius (°C) | Réaumur (°Ré) |
|---|
| Absolute Zero | -273.15 °C | -218.52 °Ré |
| Freezing Point of Water | 0 °C | 0 °Ré |
| Room Temperature | 20 °C | 16 °Ré |
| Average Body Temperature | 37 °C | 29.6 °Ré |
| Boiling Point of Water | 100 °C | 80 °Ré |