Temperature · Unit Converter

Convert Nanokelvin to Réaumur

Convert nanokelvins to degrees réaumur instantly. °Ré = (nK × 8e-10) − 218.52 — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Réaumur to Nanokelvin 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

SI Prefixed Kelvin

Nanokelvin

What is a nanokelvin?

One nanokelvin (nK) is one billionth of a kelvin (10⁻⁹ K) above absolute zero.

Origin of the nanokelvin

Formed with the SI prefix 'nano-' (from Greek 'nanos', dwarf) applied to the kelvin base unit.

Where it is used

The realm of Bose–Einstein condensates: the first condensate was created at about 170 nK in 1995, among the coldest temperatures ever achieved anywhere in the universe.

When and where it was developed

The nano- prefix was adopted by the 11th CGPM in 1960 at the launch of the International System of Units.

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.

Nanokelvin to Réaumur conversion formula

The exact relationship between nanokelvins and degrees réaumur:

°Ré = (nK × 8e-10) − 218.52
nK = (°Ré × 1.25e+9) + 273150000000

To convert nanokelvins to degrees réaumur, multiply the value by 8e-10, then subtract 218.52. To reverse, multiply the value by 1.25e+9, then add 273150000000.

Reference anchors: water freezes at 2.7315e+11 nK = 0 °Ré and boils at 3.7315e+11 nK = 80 °Ré (at standard atmospheric pressure).

How to use this converter

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

Step-by-step: convert nanokelvins to degrees réaumur

  1. Write down the temperature in nanokelvins (nK).
  2. Multiply the value by 8e-10, then subtract 218.52.
  3. The result is the same temperature expressed in degrees réaumur (°Ré).
  4. To reverse, multiply the value by 1.25e+9, then add 273150000000 — or open the Réaumur to Nanokelvin converter.

Worked examples

Example 1 — Convert 1 nK to °Ré:
(1 × 8e-10) − 218.52 = -218.5199999992 °Ré

Example 2 — Convert 100 nK to °Ré:
(100 × 8e-10) − 218.52 = -218.51999992 °Ré

Nanokelvin to Réaumur conversion table

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

Nanokelvin [nK]Réaumur [°Ré]Reference point
0-218.52Absolute zero
2.3315e+11-32Where Celsius and Fahrenheit coincide (−40°)
2.553722e+11-14.2222222222Zero Fahrenheit (0 °F)
2.7315e+110Water freezes (0 °C / 32 °F)
2.7316e+110.008Triple point of water
2.8315e+118Cool day (10 °C / 50 °F)
2.9315e+1116Room temperature (20 °C / 68 °F)
2.9815e+1120Standard laboratory temperature (25 °C)
3.0315e+1124Hot day (30 °C / 86 °F)
3.1015e+1129.6Human body temperature (37 °C / 98.6 °F)
3.1315e+1132Heat-wave day (40 °C / 104 °F)
3.2315e+1140Hot tap water (50 °C / 122 °F)
3.7315e+1180Water boils (100 °C / 212 °F)
4.5315e+11144Moderate baking oven (180 °C / 356 °F)
5.778e+124403.88Surface of the Sun (≈5,505 °C)

Frequently asked questions

What is 1 nK in °Ré?
1 nK equals -218.5199999992 °Ré — normal human body temperature.
How do I convert nanokelvins to degrees réaumur?
Use the formula °Ré = (nK × 8e-10) − 218.52: multiply the value by 8e-10, then subtract 218.52.
How do I convert degrees réaumur back to nanokelvins?
Apply the reverse formula nK = (°Ré × 1.25e+9) + 273150000000 — multiply the value by 1.25e+9, then add 273150000000 — or use the Réaumur to Nanokelvin converter.
At what temperature do the Nanokelvin and Réaumur scales read the same number?
Both scales show the same number at -218.5200001748: -218.5200001748 nK = -218.5200001748 °Ré. Set °Ré = nK 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 Nanokelvin to other temperature units

Show all Nanokelvin conversions

Sources & references

Conversion relationship (°Ré = (nK × 8e-10) − 218.52) verified against the following authoritative sources:

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