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Kelvin to Celsius Converter

Convert temperatures between Kelvin, Celsius and Fahrenheit. Enter a value, choose its scale, and get the other two instantly. Kelvin is the SI absolute scale where 0 K is absolute zero.

 

Formula

$$ °C = K - 273.15 \qquad K = °C + 273.15 \qquad °F = °C \times \tfrac{9}{5} + 32 $$

Worked example

Room temperature 300 K is \( 300 - 273.15 = 26.85\ °\text{C} \), which is \( 26.85 \times 1.8 + 32 = 80.3\ °\text{F} \). Absolute zero is 0 K = −273.15 °C.

How it works

Kelvin and Celsius share the same degree size, so converting is just a 273.15 shift: °C = K − 273.15. Kelvin starts at absolute zero, the coldest possible temperature, so it never goes negative.

Fahrenheit uses a different degree size and offset: °F = °C × 9/5 + 32. This converter takes any one scale and returns all three, which is handy in physics where absolute temperature (Kelvin) is required for gas laws and thermodynamics.

Frequently asked questions

How do you convert Kelvin to Celsius?

Subtract 273.15: °C = K − 273.15. For example, 300 K = 26.85 °C. To go back, add 273.15.

Why is absolute zero −273.15 °C?

Absolute zero is the temperature at which particle thermal motion is minimal. It defines 0 on the Kelvin scale, which corresponds to −273.15 °C.

Is a change of 1 K the same as 1 °C?

Yes. Kelvin and Celsius degrees are identical in size, so a temperature difference of 1 K equals a difference of 1 °C. They differ only in where zero sits.

How do you convert Celsius to Fahrenheit?

Multiply by 9/5 (1.8) and add 32: °F = °C × 1.8 + 32. So 26.85 °C = 80.3 °F.

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