Celsius, Fahrenheit and Kelvin
The three most common temperature scales are Celsius (used almost everywhere for weather and cooking), Fahrenheit (common in the United States) and Kelvin (the scientific SI unit that starts at absolute zero). Unlike simple ratio conversions, temperature scales have different zero points, so each conversion uses a formula rather than a single multiplier.
The formulas
°F = (°C × 9/5) + 32 • °C = (°F − 32) × 5/9 • K = °C + 273.15. Enter any value above and this tool shows the equivalent in all three scales at once, so you never have to remember the maths.
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 and add 32. For example, 20°C = 68°F.
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. For example, 98.6°F = 37°C.
What is 0 Kelvin?
0 K is absolute zero, equal to −273.15°C or −459.67°F — the lowest possible temperature.
What is normal body temperature?
About 37°C, which is 98.6°F or 310.15 K.