Convert Kelvin to Celsius.

Convert Kelvin (K) to Celsius (C). Temperature conversions are nonlinear — see the formula below.

Formula

°C = K − 273.15

Reference values

Things to watch for

• Temperature is the only non-linear conversion. There's no single multiplier — there's an offset (273.15 from C to K, 32 from C to F base) and a scale factor.
• Absolute zero is 0 K = −273.15 °C = −459.67 °F. Below that doesn't exist physically.
• For temperature differences (deltas) the offsets cancel, so a change of 1 °C equals a change of 1 K — but a change of 1 °C ≠ a change of 1 °F.

What is a kelvin?

Kelvin is the SI base unit of temperature. Zero kelvin is absolute zero (-273.15°C). One kelvin equals one degree Celsius in magnitude. Scientific work, color temperature of light sources, and thermodynamic calculations.

What is a degree Celsius?

The Celsius scale is anchored to the freezing (0°C) and boiling (100°C) points of water at standard atmospheric pressure. Weather, cooking, and everyday temperatures in almost every country.

How big is one K in real terms?

It's often easier to understand a unit when paired with familiar examples.

• 310 K — human body temperature.
• 5778 K — surface temperature of the Sun.
• 0 K — absolute zero — no molecular motion.

How to convert kelvin to degree Celsius

To convert a value from kelvin (K) to degree Celsius (°C), apply the conversion factor shown in the formula above. The calculation is the same whether you do it by hand, in a spreadsheet, or with the live converter on this page.

Steps:

1. Take your input value in K.
2. Apply the formula °C = K − 273.15.
3. The result is your value in °C.

For repeated calculations, save the formula in a spreadsheet or use the live converter at the top of this page — it handles the math automatically and displays the result as you type.

Frequently asked questions

How do I convert K to °C?

Apply the formula K → °C shown above, or just type your value into the converter at the top of this page. The result updates instantly.

Which is bigger, K or °C?

This depends on the conversion ratio in the formula. If the factor multiplied by your value gives a larger number, then °C is the smaller unit (so it takes more of them to express the same quantity). If the result is smaller, then °C is the larger unit.

When would I use K versus °C?

Both units measure temperature, so the choice depends on context. Kelvin is typically used for weather, cooking, science, and engineering; degree Celsius similarly. Most professional fields standardize on one or the other based on regional conventions or technical tradition.

How precise is this K to °C conversion?

The conversion factor shown is the internationally defined exact value (or the best-published approximation if the relationship is irrational, like degrees-to-radians). The live converter on this page uses double-precision floating-point math, accurate to about 15 significant digits — far beyond any practical engineering need.

Is the conversion ratio exact, or an approximation?

Most unit conversions between SI metric units, and between SI and US customary units, have been formally defined as exact values since the 1959 international yard-pound agreement and subsequent SI redefinitions. Exceptions are unit pairs that involve irrational numbers (radians, e.g.) or empirical conversions (like food calories, which depend on temperature). When in doubt, consult the formula at the top of this page.

Related conversions

See also