Celsius to Kelvin Converter

Convert Celsius to Kelvin instantly with this free online converter. It applies the exact K = °C + 273.15 formula and shows the result as you type — handy for weather, cooking, and science homework.

274.15
1 °C = 274.15 K

menu_bookQuick Reference

  • 0 °C = 32 °F = 273.15 K
  • 100 °C = 212 °F
  • °F = °C × 9/5 + 32
  • K = °C + 273.15

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Use the swap button to quickly reverse a conversion. Results update in real time as you type, so there is no need to press a button.

How to Convert Celsius to Kelvin

To convert Celsius to Kelvin, add 273.15: K = °C + 273.15. For example, 25°C + 273.15 = 298.15 K, standard room temperature in many physics problems.

Celsius to Kelvin Conversion Table

Celsius (°C)Kelvin (K)
-273.150
-100173.15
-40233.15
0273.15
20293.15
25298.15
37310.15
100373.15
10001273.15

Frequently Asked Questions

How do you convert Celsius to Kelvin?

Add 273.15 to the Celsius temperature. A Kelvin degree is the same size as a Celsius degree; the scales just start at different zero points.

What is 0°C in Kelvin?

0°C equals 273.15 K — the freezing point of water. Water boils at 373.15 K (100°C) at sea level.

Why does the Kelvin scale start at absolute zero?

0 K (-273.15°C) is absolute zero, the coldest temperature physically possible, where particles have minimal thermal motion. That makes Kelvin an absolute scale with no negative values, which is why science uses it.

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