Kelvin (K) to Celsius (°C)
To convert Kelvin to Celsius, subtract 273.15 from the Kelvin value. Kelvin temperatures appear in scientific papers, chemistry problems, and astrophysics. Converting back to Celsius gives an intuitive sense of the temperature — for instance, the surface of the Sun is approximately 5778 K, which is about 5505 °C. Understanding the relationship between the two scales is fundamental to GCSE and A-level science.
Frequently asked questions
Subtract 273.15 from the Kelvin value. For example, 300 K − 273.15 = 26.85 °C, and 373.15 K = 100 °C (the boiling point of water at standard pressure).
0 K = −273.15 °C, which is absolute zero — the lowest temperature theoretically possible. At this point, atoms have minimal thermal energy. It cannot be reached in practice, though scientists have come within billionths of a degree.
Normal body temperature is approximately 37 °C, which equals 37 + 273.15 = 310.15 K. This figure appears in biophysics and medical science where Kelvin is used in thermodynamic calculations.
The ideal gas law and other thermodynamic equations require an absolute temperature scale to function correctly. Using Celsius in these formulas would give wrong results because it has a non-physical zero point. In A-level and university chemistry, always convert temperatures to Kelvin before applying gas law equations.