Source unit
Celsius °C
Celsius is a unit used to measure temperature.
Celsius is the base unit for temperature conversions.
Celsius to Kelvin Converter
Reverse conversion: Kelvin to CelsiusResult
Celsius to Kelvin
Exact1 °C=274.15 K
How to convert degrees Celsius to kelvins
Conversion table
Practical and common reference values
| Celsius (°C) | Kelvin (K) | Copy converted value |
|---|---|---|
| -273.15 | 0 | |
| -40 | 233.15 | |
| 0 | 273.15 | |
| 20 | 293.15 | |
| 25 | 298.15 | |
| 37 | 310.15 | |
| 100 | 373.15 | |
| 500 | 773.15 | |
| 1000 | 1273.15 |
About Celsius and Kelvin
Degrees Celsius and kelvins use equal-sized temperature intervals but different zero points. This direction adds exactly 273.15.
Celsius as the source, Kelvin as the result
Use this direction when a temperature stated in degrees Celsius must be reported as an absolute thermodynamic temperature in kelvins for scientific, engineering, or technical work.
Result unit
Kelvin K
Kelvin is a unit used to measure temperature.
One kelvin equals -272.15 degrees Celsius.
Where Celsius-to-kelvin conversion is useful
This direction is used in laboratory records, thermodynamic equations, material data, scientific reports, and engineering calculations that require an absolute temperature rather than a relative Celsius reading.
Equal interval size, shifted zero point
A change of one degree Celsius has the same size as a change of one kelvin, but 0 °C equals 273.15 K. The conversion therefore uses an exact offset rather than a scale multiplier.
Do not add 273.15 to a temperature difference
The offset applies to absolute temperature values. A temperature increase of 10 °C is a difference of 10 K, not 283.15 K; interval conversions preserve the equal step size without shifting the zero point.
How this conversion is verified
The SI definition relates Celsius temperature to thermodynamic temperature with the exact 273.15 offset. The converter applies that affine relationship to both the live result and table values.
Standards used for this conversion
- BIPM: The International System of Units (SI), 9th editionThe kelvin, degree Celsius, equal interval size, and exact 273.15 offset.
- NIST: Guide for the Use of the International System of UnitsSI temperature notation and conversion guidance.
- NIST: Writing with SI (Metric System) UnitsSI symbol and numerical-value presentation guidance.
Kelvin symbols do not use a degree sign: write 293.15 K, not 293.15 °K.
A negative Celsius value can still represent a positive thermodynamic temperature. Only values below −273.15 °C would produce a negative kelvin result.
Frequently asked questions
6 answers for this conversion
- How do I convert Celsius to kelvin?
- Add exactly 273.15 to the Celsius value. For example, 20 °C equals exactly 293.15 K.
- What is 0 °C in kelvins?
- Zero degrees Celsius equals exactly 273.15 kelvins.
- Is the Celsius-to-kelvin conversion exact?
- Yes. The Celsius scale is related to kelvin by the exact offset 273.15, and the two scales use equal-sized intervals.
- Why does kelvin not use a degree symbol?
- Kelvin is the SI base unit name and its symbol is K. The correct form is kelvin or K, without the word degree or a degree sign.
- Do I add 273.15 to a Celsius temperature difference?
- No. One Celsius degree of temperature difference equals one kelvin of difference. The offset applies only to absolute temperature readings.
- Can a kelvin result be negative?
- Not for ordinary thermodynamic temperature in this converter. Zero kelvin is absolute zero, corresponding to −273.15 °C.
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