Convert Celsius to Kelvin

Celsius

Accepts decimals and fractions, like 1.5 or 1 1/2.

Quick presets:

Keyboard shortcut: press S to swap units.

Kelvin

Round to 2 decimals

Contextual examples

0 Celsius = 273.15 Kelvin
32 Celsius = 305.15 Kelvin
100 Celsius = 373.15 Kelvin
212 Celsius = 485.15 Kelvin

Kelvin to Celsius

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How many kelvin in a celsius?

In 1 celsius there are 274.15 kelvin. Meanwhile in 1 kelvin there are -272.15 celsius. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Celsius to Kelvin calculator above to convert any number.

* Values rounded for readability — use the calculator above for full precision

Related calculators

Use these next if you want similar conversions or tools.

Kelvin to Celsius Celsius to Fahrenheit Fahrenheit to Kelvin Celsius to Rankine Rankine to Kelvin

How does this converter work?

The Calculate Box tool to convert celsius to kelvin uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a celsius value in the box and have it instantly converted to kelvin.

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Convert Celsius to Kelvin

Convert Celsius to Kelvin in seconds with this simple calculator. Enter a temperature in °C to get the exact result in K, using the standard +273.15 formula.

Celsius

Accepts decimals and fractions, like 1.5 or 1 1/2.

Quick presets:

Keyboard shortcut: press S to swap units.

Kelvin

Round to 2 decimals

Contextual examples

0 Celsius = 273.15 Kelvin
32 Celsius = 305.15 Kelvin
100 Celsius = 373.15 Kelvin
212 Celsius = 485.15 Kelvin

Kelvin to Celsius

Swap

How many kelvin in a celsius?

* Values rounded for readability — use the calculator above for full precision

How to convert celsius to kelvin?

To convert Celsius to Kelvin, add 273.15 to the Celsius value.

Formula: K = °C + 273.15

Kelvin (K) is an absolute temperature scale, starting at absolute zero.
A change of 1°C equals a change of 1 K, so the step size is the same.

Examples:

0°C = 273.15 K
25°C = 298.15 K
-273.15°C = 0 K

Use Kelvin in science for thermodynamics, gas laws, and lab work where absolute temperature matters.

Frequently asked questions

What is the formula to convert Celsius to Kelvin?

Use this formula: K = °C + 273.15.
Add 273.15 to the Celsius value to get Kelvin.

How do you convert Kelvin to Celsius?

Use this formula: °C = K - 273.15.
Subtract 273.15 from the Kelvin value to get Celsius.

Why do you add 273.15 when converting Celsius to Kelvin?

Kelvin and Celsius use the same size degree. They just start at different zero points.
0 K is absolute zero, which equals -273.15 °C. That offset is why you add 273.15.

What is absolute zero in Celsius and Kelvin?

Absolute zero is the lowest possible temperature.
It equals 0 K and -273.15 °C.

Is Kelvin written with a degree symbol?

No. Write K, not °K.
Celsius uses the degree symbol: °C.

What are some common Celsius to Kelvin conversions?

Here are a few quick conversions:

0 °C = 273.15 K
25 °C = 298.15 K
100 °C = 373.15 K
-40 °C = 233.15 K

Can Kelvin be negative?

No. Kelvin can’t go below 0 K.
A negative Kelvin value isn’t used in standard temperature work.

Do Celsius and Kelvin have the same temperature difference?

Yes. A change of 1 °C equals a change of 1 K.
Example: from 20 °C to 25 °C is a 5 °C change, which is also 5 K.

When should you use Kelvin instead of Celsius?

Kelvin is used in many science settings, such as physics and chemistry.
It works well for gas laws and heat formulas because it starts at absolute zero.

How do you convert Celsius to Kelvin without a calculator?

Add 273 for a close estimate, then adjust by 0.15 if needed.
Example: 20 °C is about 293 K, and the exact value is 293.15 K.

Should you round Kelvin values, or keep 273.15 exact?

It depends on your needs.
For most school work, 273.15 is best. For quick estimates, rounding to 273 is often fine.

What is 0 Kelvin in Celsius?

0 K = -273.15 °C.
That value marks absolute zero.

Related calculators

Use these next if you want similar conversions or tools.

Kelvin to Celsius Celsius to Fahrenheit Fahrenheit to Kelvin Celsius to Rankine Rankine to Kelvin