Convert Celsius to Kelvin
To convert degrees Celsius to kelvins, use K = °C × 1 + 273.15: 25 °C = 298.15 K, and 0 °C = 273.15 K.
1 °C = 274.15 K
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk Celsius to Kelvin converter to paste a column from Excel.
How to Convert Celsius to Kelvin
- 1 °C = 274.15 K
- 1 K = -272.15 °C
- Example: convert 25 °C to K: 25 °C = (25 × 1 + 273.15) K = 298.15 K
Formula
K = °C × 1 + 273.15
Derivation from SI units:
- T(K) = t(°C) + 273.15 (exact, by definition)
- SI base unit, fixed by the Boltzmann constant k = 1.380649 × 10⁻²³ J/K
- Solving for K: K = °C × 1 + 273.15
Both units are defined exactly, so the factor is exact. Celsius definition: degree Celsius; Kelvin definition: kelvin.
Worked examples
- Standard laboratory temperature, 25 °C, is 298.15 K.
25 × 1 + 273.15 = 298.15 K - Liquid nitrogen boils at about -196 °C, which is 77.15 K.
-196 × 1 + 273.15 = 77.15 K
Celsius to Kelvin conversion table
| Celsius (°C) | Kelvin (K) |
|---|---|
| -273.15 °C | 0 K |
| -196 °C | 77.15 K |
| -80 °C | 193.15 K |
| -40 °C | 233.15 K |
| -20 °C | 253.15 K |
| -18 °C | 255.15 K |
| -10 °C | 263.15 K |
| 0 °C | 273.15 K |
| 4 °C | 277.15 K |
| 10 °C | 283.15 K |
| 15 °C | 288.15 K |
| 20 °C | 293.15 K |
| 21 °C | 294.15 K |
| 25 °C | 298.15 K |
| 30 °C | 303.15 K |
| 37 °C | 310.15 K |
| 40 °C | 313.15 K |
| 50 °C | 323.15 K |
| 60 °C | 333.15 K |
| 80 °C | 353.15 K |
| 100 °C | 373.15 K |
| 121 °C | 394.15 K |
| 150 °C | 423.15 K |
| 180 °C | 453.15 K |
| 200 °C | 473.15 K |
| 250 °C | 523.15 K |
| 500 °C | 773.15 K |
| 1000 °C | 1273.15 K |
Where it's used
Physics and chemistry formulas such as the ideal gas law need absolute temperature, so Celsius readings are converted to kelvin by adding 273.15. One degree Celsius and one kelvin are the same size.
Celsius to other temperature units
| Conversion | 1 °C equals |
|---|---|
| Celsius to Fahrenheit | 33.8 °F |
| Celsius to Kelvin | 274.15 K |
| Celsius to Rankine | 493.47 °R |
Frequently asked questions
Is 0 °C equal to 273 K?
Precisely, 0 °C = 273.15 K. Using 273 introduces a 0.15 K error, which matters in careful gas-law work.
What is the formula for degrees Celsius to kelvins?
K = °C × 1 + 273.15. For example, 25 °C = 298.15 K.
What is 0 °C in K?
0 °C = 273.15 K, and 100 °C = 373.15 K.
How do I convert a temperature difference from °C to K?
For a difference (an interval), ignore the offset and multiply by 1 only: a change of 10 °C is a change of 10 K.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1 and Table 4, degree Celsius.
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1, base unit definitions.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Celsius to Kelvin. Retrieved October 17, 2026, from https://scientificconverters.com/temperature/celsius-to-kelvin/
IEEE
Scientific Converters, "Convert Celsius to Kelvin," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/temperature/celsius-to-kelvin/