# Convert Temperature from Kelvin to Celsius and Back

Kelvin and Celsius are two temperature scales. The size of the "degree" for each scale is the same magnitude, but the Kelvin scale starts at absolute zero (the lowest temperature theoretically attainable), while the Celsius scale sets its zero point at the triple point of water (the point at which water can exist in solid, liquid, or gaseous states, or 32.01 F).

Converting between the Kelvin and the Celsius requires only basic arithmetic.

### Key Takeaways: Kelvin to Celsius Temperature Conversion

• The equation to convert between Kelvin and Celsius is: C = K - 273.15.
• While the size of the degree is the same between Kelvin and Celsius, there is no point at which the two scales are equal: A Celsius temperature will always be higher than Kelvin.
• Celsius temperatures can be negative; Kelvin goes down to absolute zero (no negative temperature).

## Conversion Formula

The formula to convert Kelvin into Celsius is C = K - 273.15. All that is needed to convert Kelvin to Celsius is one simple step:

Take your Kelvin temperature and subtract 273.15. Your answer will be in Celsius. The K does not use the word degree or the symbol; depending on the context, generally one or the other (or simply C) is used to report a Celsius temperature.

## Kelvin to Celsius

How many degrees Celsius is 500 K?

C = 500 - 273.15
500 K = 226.85 C

Let's convert normal body temperature from Kelvin to Celsius. Human body temperature is 310.15 K. Put the value into the equation to solve for degrees Celsius:

C = K - 273.15
C = 310.15 - 273.15
Human body temperature = 37 C

## Reverse Conversion: Celsius to Kelvin

Similarly, it's easy to convert a Celsius temperature to the Kelvin scale. You can either use the formula given above or use K = C + 273.15.

For example, let's convert the boiling point of water to Kelvin. The boiling point of water is 100 C. Plug the value into the formula:

K = 100 + 273.15
K = 373.15