Convert Reaumur to Newton easily.

Ever wondered how 18th-century scientists measured temperature before Celsius and Fahrenheit dominated? Enter the Reaumur and Newton scales, two historical systems that once rivaled modern standards. While you won’t find them in today’s weather apps, converting between these units offers a fascinating glimpse into the evolution of thermal measurement. Whether you're deciphering antique recipes or analyzing old laboratory notes, understanding how to switch from Reaumur to Newton (or vice versa) bridges the gap between past and present.

Unit definitions

What is a Reaumur (°Ré)?

The Reaumur scale, introduced by French scientist René Antoine Ferchault de Réaumur in 1730, sets water’s freezing point at 0°Ré and boiling point at 80°Ré. Each degree represents 1/80th of this interval. It was widely used in Europe, especially for cheese production and meteorology, until the Celsius scale replaced it.

Symbol: °Ré
Common uses: Historical food preparation, early industrial processes
Definition: 1°Ré = 1.25°C

What is a Newton (°N)?

Isaac Newton dabbled in thermometry around 1701, creating a scale where water freezes at 0°N and "body heat" (likely his own) marked 12°N. He used linseed oil thermometers, calibrating them against melting snow and human skin. Though innovative, the scale lacked practicality and was soon overshadowed.

Symbol: °N
Common uses: Early physics experiments, historical academic studies
Definition: 1°N ≈ 3.03°C

Conversion formula

To convert Reaumur to Newton:
Newton = Reaumur × 0.4125
Or equivalently:
°N = °Ré × 33/80

For Newton to Reaumur:
Reaumur = Newton ÷ 0.4125
Simplified:
°Ré = °N × 80/33

Example calculations

1. Converting 20°Ré to Newton:
   20 × 0.4125 = 8.25°N
2. Converting 50°Ré to Newton:
   50 × 0.4125 = 20.625°N

Conversion tables

Reaumur to Newton

Newton to Reaumur

From linseed oil to cheese caves, a tale of two scales

The Reaumur scale’s 80-degree spread between freezing and boiling water made it intuitive for pre-industrial applications. Réaumur himself tested alcohol thermometers in wine cellars, while Swiss cheesemakers adopted the scale to monitor fermentation. Meanwhile, Newton’s 12-degree system reflected his experimental ethos. He reportedly calibrated his thermometers by placing them in snow (0°N) and against his own body (12°N) , though skeptics argue he might’ve used candle flames instead. Both scales faded as standardized systems emerged, but their legacy persists in antique instruments and niche scientific discussions.

Interesting facts

1. Newton’s original thermometer fluids included linseed oil and beer.
2. The Reaumur scale was still used in some Russian factories until the 1920s.
3. A temperature of 80°Ré equals 100°C, matching water’s boiling point.
4. Newton never published his scale formally, it appeared in personal notes.
5. Réaumur’s work on insects influenced his approach to thermal measurement.

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