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Temperature Converter

Convert Celsius to Kelvin.

Input the value of celsius below to convert instantly to kelvin with standard conversions, definitions, and equations.

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°C
K
°C + 273.15 = K Add 273.15 to the temperature in Celsius to get the temperature in Kelvin.

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Overview

About converting celsius to kelvin

Celsius to Kelvin is the everyday-to-absolute conversion used in physics, chemistry, and engineering, where temperatures are measured from absolute zero rather than the freezing point of water.

Kelvin and Celsius degrees are exactly the same size, so the only change is the zero point: K = °C + 273.15. Absolute zero, the coldest possible temperature, is 0 K = −273.15 °C. Room temperature of 25 °C is 298.15 K, and water boils at 373.15 K.

Because the two scales share a degree size, a temperature difference of 1 °C equals a difference of 1 K — which is why scientific formulas often use kelvin and celsius interchangeably for changes in temperature, even though their absolute values differ by 273.15.

Practical Tips
  • Just add 273.15 — no multiplication is involved.
  • Kelvin is written without a degree symbol: 300 K, not 300 °K.

How to Convert Celsius to Kelvin

To convert celsius to kelvin, we use the official conversion formulas. Below is the mathematical formula, plain-English explanation, and a worked example.

celsius-to-kelvin-formula.py
# Mathematical Formula
°C + 273.15 = K
# Worked Example (5 °C)
5 °C + 273.15 = 278.1500 K
What is a Celsius?

Celsius (°C)

The standard metric temperature scale, where water freezes at 0°C and boils at 100°C.

What is a Kelvin?

Kelvin (K)

The SI unit of thermodynamic temperature, starting at absolute zero (0 K = -273.15°C).

Celsius to Kelvin Conversion Table

Celsius (°C) Kelvin (K)
1 °C 274.15 K
2 °C 275.15 K
3 °C 276.15 K
5 °C 278.15 K
10 °C 283.15 K
15 °C 288.15 K
20 °C 293.15 K
25 °C 298.15 K
50 °C 323.15 K
100 °C 373.15 K
250 °C 523.15 K
500 °C 773.15 K
1000 °C 1273.15 K

Kelvin to Celsius Conversion Table

Kelvin (K) Celsius (°C)
1 K -272.15 °C
2 K -271.15 °C
3 K -270.15 °C
5 K -268.15 °C
10 K -263.15 °C
15 K -258.15 °C
20 K -253.15 °C
25 K -248.15 °C
50 K -223.15 °C
100 K -173.15 °C
250 K -23.15 °C
500 K 226.85 °C
1000 K 726.85 °C
Questions

Frequently Asked Questions

How do I convert celsius to kelvin?

Multiply the value in celsius by the conversion factor 274.15. For example, to convert 5 celsius to kelvin: 5 × 274.15 = 1370.7500 K.

What is the conversion factor from celsius to kelvin?

The conversion factor is 274.15. One celsius is equal to 274.15 kelvin.

What is the reverse conversion from kelvin to celsius?

To convert kelvin back to celsius, multiply by -2.721500e+2 (or divide the value by 274.15). One kelvin is equal to -2.721500e+2 celsius.

What temperature is absolute zero in Celsius?

Absolute zero is exactly -273.15°C, or 0 Kelvin.

How do you convert Celsius to Fahrenheit?

Multiply the Celsius temperature by 9/5 (1.8) and then add 32. For example, 10°C is (10 * 1.8) + 32 = 50°F.

At what temperature do Celsius and Fahrenheit meet?

Celsius and Fahrenheit are equal at exactly -40° (i.e. -40°C = -40°F).

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