Convert between Celsius and Kelvin. Essential for science, physics, chemistry, and thermodynamics.
Last updated: March 2026 | By Patchworkr Team
Celsius and Kelvin are two different temperature scales. Celsius is a relative scale based on water's freezing (0°C) and boiling (100°C) points. Kelvin is an absolute scale that starts at absolute zero, the coldest temperature theoretically possible.
In Kelvin, there is no negative temperature. The conversion is simple: just add 273.15 to any Celsius temperature. Absolute zero is 0 K, which equals −273.15°C.
Important note on notation: Kelvin temperatures are written as just K (not °K). For example: 298 K (not 298°K).
Kelvin is the SI unit for thermodynamic temperature and is the standard scale in physics, chemistry, and engineering.
Add 273.15 to any Celsius temperature to get Kelvin. The 273.15 is an offset that represents absolute zero: the temperature where molecular motion theoretically stops.
Subtract 273.15 to convert Kelvin back to Celsius.
Convert 25°C to Kelvin (step-by-step)
Step 1: Take the Celsius value
Step 2: Add 273.15
| Celsius | Kelvin |
|---|---|
| -273.15 °C | 0 K |
| -50 °C | 223.15 K |
| 0 °C | 273.15 K |
| 10 °C | 283.15 K |
| 20 °C | 293.15 K |
| 25 °C | 298.15 K |
| 37 °C | 310.15 K |
| 50 °C | 323.15 K |
| 100 °C | 373.15 K |
| 500 °C | 773.15 K |
Add 273.15 to the Celsius value.
0 K = -273.15°C, the lowest possible temperature.
Kelvin is an absolute scale starting at zero, ideal for scientific calculations.
Around 293-298 K (20-25°C).
273.15 K (freezing point of water).
No, Kelvin cannot go below zero.
No, just write K, not °K.
373.15 K (boiling point of water).
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