Temperature · Unit Converter

Convert Réaumur to Millikelvin

Convert degrees réaumur to millikelvins instantly. mK = (°Ré × 1250) + 273150 — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Millikelvin to Réaumur converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Temperature category 2 min read Published Last reviewed Updated

Units explained

Historical Scales

Réaumur

What is a degree 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).

Origin of the degree réaumur

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.

Where it is used

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.

When and where it was developed

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.

SI Prefixed Kelvin

Millikelvin

What is a millikelvin?

One millikelvin (mK) is one thousandth of a kelvin (10⁻³ K), measured upward from absolute zero.

Origin of the millikelvin

Formed with the SI prefix 'milli-' (from Latin 'mille', a thousand) applied to the kelvin base unit.

Where it is used

Cryogenics and low-temperature physics — the dilution refrigerators that cool superconducting quantum computers operate at roughly 10–20 mK.

When and where it was developed

The milli- prefix belongs to the original metric system of 1795 and was carried into the SI in 1960; the kelvin became an SI base unit in 1954.

Réaumur to Millikelvin conversion formula

The exact relationship between degrees réaumur and millikelvins:

mK = (°Ré × 1250) + 273150
°Ré = (mK × 0.0008) − 218.52

To convert degrees réaumur to millikelvins, multiply the value by 1250, then add 273150. To reverse, multiply the value by 0.0008, then subtract 218.52.

Reference anchors: water freezes at 0 °Ré = 273150 mK and boils at 80 °Ré = 373150 mK (at standard atmospheric pressure).

How to use this converter

Type a value into the calculator. The result in millikelvins updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Millikelvin to Réaumur converter for the reverse direction.

Step-by-step: convert degrees réaumur to millikelvins

  1. Write down the temperature in degrees réaumur (°Ré).
  2. Multiply the value by 1250, then add 273150.
  3. The result is the same temperature expressed in millikelvins (mK).
  4. To reverse, multiply the value by 0.0008, then subtract 218.52 — or open the Millikelvin to Réaumur converter.

Worked examples

Example 1 — Convert 29.6 °Ré to mK (human body temperature):
(29.6 × 1250) + 273150 = 310150 mK

Example 2 — Convert 80 °Ré to mK (the boiling point of water):
(80 × 1250) + 273150 = 373150 mK

Réaumur to Millikelvin conversion table

Physically meaningful reference temperatures, from absolute zero to the surface of the Sun, converted from degrees réaumur to millikelvins:

Réaumur [°Ré]Millikelvin [mK]Reference point
-218.520Absolute zero
-32233150Where Celsius and Fahrenheit coincide (−40°)
-14.2222222222255372.2222222222Zero Fahrenheit (0 °F)
0273150Water freezes (0 °C / 32 °F)
0.008273160Triple point of water
8283150Cool day (10 °C / 50 °F)
16293150Room temperature (20 °C / 68 °F)
20298150Standard laboratory temperature (25 °C)
24303150Hot day (30 °C / 86 °F)
29.6310150Human body temperature (37 °C / 98.6 °F)
32313150Heat-wave day (40 °C / 104 °F)
40323150Hot tap water (50 °C / 122 °F)
80373150Water boils (100 °C / 212 °F)
144453150Moderate baking oven (180 °C / 356 °F)
4403.885778000Surface of the Sun (≈5,505 °C)

Frequently asked questions

What is 29.6 °Ré in mK?
29.6 °Ré equals 310150 mK — normal human body temperature.
How do I convert degrees réaumur to millikelvins?
Use the formula mK = (°Ré × 1250) + 273150: multiply the value by 1250, then add 273150.
How do I convert millikelvins back to degrees réaumur?
Apply the reverse formula °Ré = (mK × 0.0008) − 218.52 — multiply the value by 0.0008, then subtract 218.52 — or use the Millikelvin to Réaumur converter.
At what temperature do the Réaumur and Millikelvin scales read the same number?
Both scales show the same number at -218.6949559648: -218.6949559648 °Ré = -218.6949559648 mK. Set mK = °Ré in the conversion formula and solve to verify it.
Can a temperature be below absolute zero?
No. Absolute zero (0 K = −273.15 °C = −459.67 °F) is the floor of the thermodynamic temperature scale. The calculator flags any input that would fall below it.

Convert Réaumur to other temperature units

Show all Réaumur conversions

Sources & references

Conversion relationship (mK = (°Ré × 1250) + 273150) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.