Temperature Converter

How it is calculated

The converter takes one temperature and the scale it is in (C, F or K) and shows all three. Internally it first converts to Celsius: from Fahrenheit C = (F − 32) × 5 / 9, from Kelvin C = K − 273.15, and Celsius stays as it is. Then F = C × 9 / 5 + 32 and K = C + 273.15. Results are rounded to two decimals. If no scale is given, Celsius is assumed. The tool does not reject values below absolute zero (−273.15 °C, 0 K, −459.67 °F), so check that your input is physically possible. The size of one degree is the same in Celsius and Kelvin, but the Fahrenheit degree is smaller (5/9 of a Celsius degree).

Common mistakes

• Choosing the wrong source scale, so a Fahrenheit reading entered as Celsius gives an impossible figure such as 98.6 °C.
• Converting a temperature difference with the offset: a rise of 10 °C is a rise of 18 °F, not 50 °F, because differences scale by 9/5 without adding 32.
• Using 273 instead of 273.15 for Kelvin when precision matters.
• Writing "° K" or negative Kelvin values; Kelvin has no degree sign and cannot go below zero.
• Halving the Fahrenheit number to estimate Celsius; the quick rule is subtract 32 first, then multiply by about 0.56.