Unit converter
Kelvin to Celsius Converter
Take a kelvin reading and express it in everyday Celsius. Laboratory instruments, physics problems and scientific datasets report absolute temperature in kelvin, but most people picture warmth in Celsius, so the value often needs translating back. Light-bulb packaging is another source: a 4000 K panel means little until you relate it to familiar temperatures. Enter a figure in kelvin and the tool gives degrees Celsius, with a quick table of the points searched most. It is handy for checking lab output, working through thermodynamics, or sense-checking a kelvin figure against the temperatures you know.
Common Kelvin to Celsius values
| Kelvin | Celsius |
|---|---|
| 0 K | -273.15 °C |
| 100 K | -173.15 °C |
| 200 K | -73.15 °C |
| 273.15 K | 0 °C |
| 300 K | 26.85 °C |
| 310 K | 36.85 °C |
| 373.15 K | 100 °C |
How to convert
- Start with the temperature in kelvin.
- Subtract 273.15, the gap between absolute zero and the Celsius zero point.
- The result is the temperature in degrees Celsius.
- No multiplication is required, since a kelvin step and a Celsius step are identical in size.
- Going back the other way means adding 273.15 to a Celsius value to return to kelvin.
°C = K - 273.15
Because kelvin and Celsius increase at the same rate, switching between them is purely a matter of moving the zero. Kelvin counts upward from absolute zero, while Celsius counts from the freezing point of water, which sits 273.15 higher. Subtracting 273.15 from a kelvin reading drops it onto the Celsius scale without any rescaling.
- K
- the temperature in kelvin you start with
- 273.15
- the distance from absolute zero up to the Celsius zero
- °C
- the resulting temperature in degrees Celsius
Worked example
A reading of 300 K from a lab probe is 300 minus 273.15, which is 26.85°C, a touch above room temperature. A cryogenic 77 K (liquid nitrogen) comes to 77 minus 273.15, or -196.15°C.
Key facts
- 0 K is absolute zero, equal to -273.15°C.
- Water freezes at 273.15 K (0°C) and boils at 373.15 K (100°C).
- A typical 293.15 K laboratory reading is about 20°C.
- One kelvin and one Celsius degree cover the same temperature span.
Tips
- Subtracting a round 273 is close enough for a quick estimate; keep the .15 only when precision counts.
- After a thermodynamics calculation in kelvin, convert the final answer to Celsius to judge whether it looks sensible.
Frequently asked questions
What is 300 K in Celsius?+
300 K is 300 - 273.15, which equals 26.85°C, close to a warm room.
What does 0 K convert to?+
0 K is absolute zero, which is -273.15°C, the coldest temperature possible.
Why subtract 273.15 exactly?+
That number is the fixed distance between the kelvin zero (absolute zero) and the Celsius zero (water freezing), so removing it shifts an absolute reading back onto the everyday scale.
Can the answer be negative?+
Yes. Any kelvin value below 273.15 gives a sub-zero Celsius temperature, which is perfectly normal for cold conditions.
Things to watch
- Kelvin carries no degree symbol, so read the input as plain kelvin, not "degrees kelvin".
- A kelvin input below zero is impossible; treat one as a data-entry error rather than converting it.
Sources
Last updated: 2026-01-01
Conversions use internationally defined factors. Provided for general use; verify critical measurements independently.