Kelvin (K)
SI base unit of thermodynamic temperature, defined by fixing the Boltzmann constant k = 1.380649e-23 J/K.
What is a kelvin?
- Symbol
- K
- Quantity
- Temperature
- Unit system
- SI
- Definition
- SI base unit of thermodynamic temperature, defined by fixing the Boltzmann constant k = 1.380649e-23 J/K.
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
The SI base unit of temperature, starting at absolute zero. Used in physics, chemistry and for the color temperature of light.
Kelvin in other temperature units
- °C = K − 273.15Kelvin to Degree Celsius converter
- °F = K × 1.8 − 459.67Kelvin to Degree Fahrenheit converter
- °R = K × 1.8Degree Rankine
Kelvin quick reference
| Kelvin | Degree Celsius | Degree Fahrenheit | Degree Rankine |
|---|---|---|---|
| 0 K | = -273.15 °C | = -459.67 °F | = 0 °R |
| 200 K | = -73.15 °C | = -99.67 °F | = 360 °R |
| 250 K | = -23.15 °C | = -9.67 °F | = 450 °R |
| 273.15 K | = 0 °C | = 32 °F | = 491.67 °R |
| 293.15 K | = 20 °C | = 68 °F | = 527.67 °R |
| 298.15 K | = 25 °C | = 77 °F | = 536.67 °R |