Temperature converter

Celsius to
Kelvin

Convert Celsius to Kelvin for scientific and technical work.

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How to convert celsius to kelvin

Apply the documented celsius-to-kelvin relationship below, keeping the full stored constant until the displayed result is rounded.

Kelvin = Celsius + 273.15

For example, 10 °C equals 283.15 K.

Celsius to Kelvin reference table

CelsiusKelvin
1 °C274.15 K
5 °C278.15 K
10 °C283.15 K
25 °C298.15 K
50 °C323.15 K
100 °C373.15 K

Method and quality checks

Calculation
Kelvin = Celsius + 273.15. The calculator keeps the stored factor through the operation and rounds only the displayed result to the selected or page-supported precision.
Unit convention
This is a point-temperature conversion, so the scale offset is included. Temperature intervals use a different rule.
Input validation
Finite numeric inputs are accepted, while values below absolute zero for the source scale are rejected.
Reasonableness check
10 °C produces 283.15 K. Check the direction and approximate scale before relying on a more precise displayed value.

Deeper method: Temperature scales compared.

Celsius and kelvin share the same interval size

A temperature change of 1 degree Celsius has the same size as a change of 1 kelvin. The scales differ only in origin: add exactly 273.15 to a Celsius temperature to express it in kelvins, so 0 °C equals 273.15 K.

  • Write kelvin values with K, not a degree sign.
  • A Celsius temperature below −273.15 °C would convert below absolute zero and is not physically valid.
  • For temperature differences, the numerical values in degrees Celsius and kelvins are identical.

Reference: NIST: Kelvin introduction.