Convert 4 Kelvin (K) to Réaumur (°Ré).

4 Kelvin equals -215.32 Réaumur. Apply the formula °Ré = (K - 273.15) × 4/5.

4 Kelvin = -215.32 Réaumur

Worked example: converting Kelvin to Réaumur

Step 1 — start with the formula. °Ré = (K - 273.15) × 4/5
Step 2 — substitute your figure. Apply the formula to 4 K.
Step 3 — read the result. 4 K = -215.32 °Ré
Step 4 — check it in reverse. K = (°Ré × 5/4) + 273.15 returns 4 K, which matches the figure you started with.

Temperature Converter

5 units available

Decimals:

From

To

-215.32

4 K = -215.32 °Ré

Formula:

°Ré = (K - 273.15) × 4/5

With your value: 4 K = -215.32 °Ré

Other Kelvin to Réaumur conversions

1 K to °Ré 2 K to °Ré 3 K to °Ré 5 K to °Ré 6 K to °Ré 7 K to °Ré 8 K to °Ré Full Kelvin to Réaumur converter

Kelvin to Réaumur Conversion Table

Kelvin (K)	Réaumur (°Ré)
0.5	-218.12
1	-217.72
2	-216.92
5	-214.52
10	-210.52
15	-206.52
20	-202.52
25	-198.52
50	-178.52
100	-138.52
250	-18.52
500	181.48
1000	581.48

Réaumur to Kelvin Conversion Table

Réaumur (°Ré)	Kelvin (K)
0.5	273.775
1	274.4
2	275.65
5	279.4
10	285.65
15	291.9
20	298.15
25	304.4
50	335.65
100	398.15
250	585.65
500	898.15
1000	1,523.15

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Kelvin (K)

Temperature

SI definition

Traceable to the kelvin, defined by fixing the Boltzmann constant at 1.380 649 × 10⁻²³ J/K. Celsius and Fahrenheit are exact affine transforms of the kelvin scale.

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

Réaumur (°Ré)

Temperature

SI definition

Traceable to the kelvin, defined by fixing the Boltzmann constant at 1.380 649 × 10⁻²³ J/K. Celsius and Fahrenheit are exact affine transforms of the kelvin scale.

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Kelvin to Réaumur

This conversion uses an offset formula, so it cannot be described by a single multiplication factor.

Formula: °Ré = (K - 273.15) × 4/5

Reverse: K = (°Ré × 5/4) + 273.15

Step-by-Step Example

Start with your value in Kelvin. For example: 5 K
Apply °Ré = (K - 273.15) × 4/5
The result is: -214.52 °Ré

About Kelvin

The Kelvin scale is the SI unit of temperature that starts at absolute zero (−273.15°C). It is used extensively in scientific research.

Fun Fact: At 0 Kelvin (absolute zero), all molecular motion stops. It has never been fully achieved in a laboratory.

Common uses: physics, astronomy, chemistry.

About Réaumur

The Réaumur scale sets water's freezing point at 0 °Ré and its boiling point at 80 °Ré. It survives in a few European cheese and syrup recipes.

Common uses: historic recipes, history of science.

Frequently Asked Questions

What is 4 Kelvin in Réaumur?

4 Kelvin equals -215.32 Réaumur.

How many Réaumur are in 1 Kelvin?

There are exactly -217.72 Réaumur in 1 Kelvin.

What is the formula to convert Kelvin to Réaumur?

The formula to convert Kelvin to Réaumur is: °Ré = (K - 273.15) × 4/5. For example, to convert 10 Kelvin to Réaumur, you would apply the formula to 10.

What is a Kelvin?