Source unit
Kelvin K
Kelvin is a unit used to measure temperature.
A reading of 1 K corresponds to -272.15 °C. Differences on an offset scale require interval conversion.
Kelvin to Celsius Converter
Reverse conversion: Celsius to KelvinConverter
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Kelvin to Celsius
Exact1 K=-272.15 °C
How to convert kelvins to degrees Celsius
Formula, method and accuracy
A reading of 1 K corresponds to -272.15 °C. This is a point conversion, not a factor for intervals.
Subtract exactly 273.15 from the kelvin value. The converter rejects absolute temperatures below 0 K rather than extending the ordinary thermodynamic scale past absolute zero.
°C = K × 1 − 273.15
1 K × 1 − 273.15 = -272.15 °C
- Operation
- Multiply and subtract
- Method
- Affine
- Accuracy
- Exact ratio
Conversion table
Practical and common reference values
| Kelvin (K) | Celsius (°C) | Copy converted value |
|---|---|---|
| 0 | -273.15 | |
| 1 | -272.15 | |
| 77 | -196.15 | |
| 273.15 | 0 | |
| 293.15 | 20 | |
| 298.15 | 25 | |
| 310.15 | 37 | |
| 373.15 | 100 | |
| 1000 | 726.85 |
About Kelvin and Celsius
Kelvin expresses absolute thermodynamic temperature; Celsius uses the same interval size with a zero point 273.15 kelvins above absolute zero.
Kelvin as the source, Celsius as the result
Use this direction when an absolute temperature from scientific data, a material specification, or a thermodynamic calculation must be communicated on the familiar Celsius scale.
Result unit
Celsius °C
Celsius is a unit used to measure temperature.
Celsius is the calculation reference for temperature readings in this converter, not necessarily the SI base unit.
Where kelvin-to-Celsius conversion is useful
Kelvin-to-Celsius conversion helps interpret laboratory temperatures, material properties, scientific publications, color-temperature context, and engineering data for readers or controls that use degrees Celsius.
Subtracting the exact scale offset
Kelvin and Celsius increments are the same size. Their numerical values differ by exactly 273.15, so converting an absolute kelvin reading requires subtraction rather than proportional scaling.
A negative Celsius result can be valid
Kelvin values between 0 K and 273.15 K convert to negative Celsius temperatures without becoming invalid. The physical lower bound is 0 K, not 0 °C.
How this conversion is verified
The SI definition gives Celsius temperature as the kelvin value minus exactly 273.15. The converter uses that offset unchanged in the current result and all generated references.
Standards used for this conversion
- BIPM: The International System of Units (SI), 9th editionThe thermodynamic-temperature scale and its exact relation to degrees Celsius.
- NIST: Guide for the Use of the International System of UnitsCorrect SI temperature symbols and conversion practice.
- NIST: Writing with SI (Metric System) UnitsPresentation of SI quantities and unit symbols.
For a quick check, 300 K is about 27 °C. Subtract 273.15 when the exact converted value is needed.
Temperature intervals need no 273.15 subtraction: a change of 25 K has the same numerical size as a change of 25 °C.
Frequently asked questions
6 answers for this conversion
- How do I convert kelvins to Celsius?
- Subtract exactly 273.15 from the kelvin value. For example, 300 K equals exactly 26.85 °C.
- What is 273.15 K in Celsius?
- A temperature of 273.15 K equals exactly 0 °C.
- What is absolute zero in Celsius?
- Absolute zero is 0 K, which equals exactly −273.15 °C on the Celsius scale.
- Can kelvin convert to a negative Celsius value?
- Yes. Any kelvin value below 273.15 K and at or above 0 K converts to a negative Celsius temperature.
- Is one kelvin the same interval as one degree Celsius?
- Yes. Their interval sizes are equal. The difference between the scales is the zero point used for absolute readings.
- Should kelvin be written with a degree sign?
- No. Write K for kelvin and °C for degree Celsius. For example, write 300 K, not 300 °K.
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