Converters
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin.
Free to use — no sign-up or login.
Celsius, Fahrenheit, and Kelvin share linear formulas. °F = °C × 9/5 + 32, and K = °C + 273.15. A reading of 20 °C is 68 °F and 293.15 K.
Heat as energy, in joules or kilowatt-hours, is the energy converter. This page only moves a temperature between scales.
Water and body temperature
At sea level, water freezes at 0 °C, 32 °F, and 273.15 K, and it boils at 100 °C, 212 °F, and 373.15 K. Minus 40 is the same number on Celsius and Fahrenheit.
Absolute zero
Zero kelvin is −273.15 °C. The page refuses a temperature below 0 K. Kelvin is written without a degree sign.
Worked example: 20 °C
From Celsius to Fahrenheit, 20 displays as 68. From Celsius to kelvin, 20 displays as 293.15.
\[ 20^{\circ}\mathrm{C}=68^{\circ}\mathrm{F}=293.15\,\mathrm{K} \]
Frequently asked questions
What is 20 °C in Fahrenheit?
68 °F.
What is 20 °C in kelvin?
293.15 K.
Where do Celsius and Fahrenheit meet?
At −40. That number is the same on both scales.
Can I enter a negative kelvin?
No. Temperatures below 0 K are refused.
Does this page include Rankine?
No. The scales are Celsius, Fahrenheit, and kelvin.
References
Assumptions and limitations
Three scales only. Boiling and freezing notes assume sea-level water. Nothing below absolute zero is converted.