Fahrenheit and Celsius thermometer. Credit: Todd Helmenstine

The Kelvin temperature scale is sometimes called the absolute temperature because the zero point is the absolute limit of the coldest anything can get. Most of the time, any data you take will be in the Celsius temperature scale since there aren’t that many Kelvin thermometers in classroom laboratories. Sometimes, you need to perform a conversion between the two scales. Fortunately, this is straightforward for Kelvin and Celsius. The formula for converting Kelvin to Celsius is:

°C = K – 273.15

where °C is the temperature in Celsius K is the temperature in Kelvin

Example Problem: In many ideal gas problems, room temperature is considered to be at 300 K to make calculations easier. What is this temperature in Celsius?

Solution:

°C = K – 273.15 °C = 300 – 273.15 °C = 26.85 °C

Answer: Room temperature is a pretty warm 26.85 °C for these calculations.