Celsius to Kelvin converter

Type a temperature in Celsius and the calculator returns Kelvin using K = °C + 273.15. Kelvin is the SI base unit of temperature; 0 K is absolute zero.

Kelvin
298.15 K
Fahrenheit
77 °F
Rankine
536.67 °R
Formula
K = °C + 273.15

Quick reference

  • −273.15 °C = 0 K (absolute zero)
  • 0 °C = 273.15 K (water freezing)
  • 25 °C = 298.15 K (room temperature)
  • 100 °C = 373.15 K (water boiling)

FAQ

Why is there no degree sign with K?

By SI convention Kelvin is written without "°" — just "K". The Kelvin scale is a thermodynamic absolute scale, not a "degrees from a reference" scale.

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