Convert Réaumur to Newton
Convert degrees réaumur to degrees newton instantly. 1 °Ré = 0.4125 °N — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Newton to Réaumur converter for the reverse conversion.
Units explained
Réaumur
The degree Réaumur (°Ré) sets the freezing point of water at 0 °Ré and the boiling point at 80 °Ré, so one degree Réaumur equals exactly 1.25 kelvins (5/4 K).
Devised by French scientist René Antoine Ferchault de Réaumur using alcohol thermometers whose working liquid expanded 80 parts per thousand between the freezing and boiling points of water — the origin of the 80-degree span.
Once dominant across 18th- and 19th-century Europe, especially France, Germany, and Russia. It survives today mainly in traditional cheese-making — Parmigiano-Reggiano and Swiss alpine dairies still specify milk temperatures in °Ré.
Introduced by Réaumur in Paris in 1730; it faded from general use after France adopted the Celsius scale with the metric system in the 1790s.
Newton
The degree Newton (°N) sets the freezing point of water at 0 °N and the boiling point at 33 °N, making one degree Newton equal to exactly 100/33 kelvins (about 3.03 K) — the largest degree of any classic scale.
Devised by Isaac Newton using linseed-oil thermometers and a ladder of everyday reference points such as melting snow and the heat of the human body, published anonymously around 1701.
Never adopted for practical measurement, but historically important: Newton's idea of anchoring a scale to two reproducible fixed points directly influenced Celsius's centigrade approach four decades later.
Published by Isaac Newton in the Philosophical Transactions of the Royal Society in London, around 1701.
Réaumur to Newton conversion formula
The exact relationship between degrees réaumur and degrees newton:
To convert degrees réaumur to degrees newton, multiply the value in degrees réaumur by 33/80. To reverse, multiply the value in degrees newton by 80/33.
Both units count upward from absolute zero, so 0 °Ré = 0 °N and the relationship is a pure ratio.
How to use this converter
Type a value into the calculator. The result in degrees newton updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Newton to Réaumur converter for the reverse direction.
Step-by-step: convert degrees réaumur to degrees newton
- Write down the temperature in degrees réaumur (°Ré).
- Multiply the value in degrees réaumur by 33/80.
- The result is the same temperature expressed in degrees newton (°N).
- To reverse, multiply the value in degrees newton by 80/33 — or open the Newton to Réaumur converter.
Worked examples
Example 1 — Convert 29.6 °Ré to °N (human body temperature):
29.6 × 33/80 = 12.21 °N
Example 2 — Convert 80 °Ré to °N (the boiling point of water):
80 × 33/80 = 33 °N
Réaumur to Newton conversion table
Physically meaningful reference temperatures, from absolute zero to the surface of the Sun, converted from degrees réaumur to degrees newton:
| Réaumur [°Ré] | Newton [°N] | Reference point |
|---|---|---|
| -218.52 | -90.1395 | Absolute zero |
| -32 | -13.2 | Where Celsius and Fahrenheit coincide (−40°) |
| -14.2222222222 | -5.8666666667 | Zero Fahrenheit (0 °F) |
| 0 | 0 | Water freezes (0 °C / 32 °F) |
| 0.008 | 0.0033 | Triple point of water |
| 8 | 3.3 | Cool day (10 °C / 50 °F) |
| 16 | 6.6 | Room temperature (20 °C / 68 °F) |
| 20 | 8.25 | Standard laboratory temperature (25 °C) |
| 24 | 9.9 | Hot day (30 °C / 86 °F) |
| 29.6 | 12.21 | Human body temperature (37 °C / 98.6 °F) |
| 32 | 13.2 | Heat-wave day (40 °C / 104 °F) |
| 40 | 16.5 | Hot tap water (50 °C / 122 °F) |
| 80 | 33 | Water boils (100 °C / 212 °F) |
| 144 | 59.4 | Moderate baking oven (180 °C / 356 °F) |
| 4403.88 | 1816.6005 | Surface of the Sun (≈5,505 °C) |
Frequently asked questions
How many degrees newton is 1 degree réaumur?
How do I convert degrees réaumur to degrees newton?
How do I convert degrees newton back to degrees réaumur?
How many degrees newton is 80 degrees réaumur?
Can a temperature be below absolute zero?
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Modern Standard Scales (4 units)
Historical Scales (3 units)
Scientific & Fixed-Point (3 units)
Sources & references
Conversion relationship (1 °Ré = 0.4125 °N) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- BIPM — International Temperature Scale of 1990 (ITS-90)
The internationally agreed practical temperature scale, defining fixed points (including the triple point of water at 273.16 K) and interpolation instruments used by national metrology institutes for thermometer calibration worldwide.
- CODATA Internationally Recommended Values of the Fundamental Physical Constants
Committee on Data of the International Science Council; authoritative source for the masses of fundamental particles (electron, proton, neutron) and the atomic mass constant.