Unit converter

Temperature Converter

Convert Celsius, Fahrenheit, Kelvin, and Rankine temperatures instantly. Use the formula table and common reference values for weather, cooking, science, and engineering conversions.

Temperature input

Convert from any unit

C, F, K, R
Celsius100°C
Fahrenheit212°F
Kelvin373.15 K
Rankine671.67°R

Temperature conversion formulas

ConversionFormula
Celsius to Fahrenheit°F = °C x 9/5 + 32
Fahrenheit to Celsius°C = (°F - 32) x 5/9
Celsius to KelvinK = °C + 273.15
Kelvin to Celsius°C = K - 273.15
Fahrenheit to Rankine°R = °F + 459.67
Rankine to Fahrenheit°F = °R - 459.67

Common temperature reference table

Reference pointCelsiusFahrenheitKelvin
Absolute zero-273.15°C-459.67°F0 K
Water freezes0°C32°F273.15 K
Room temperature20°C68°F293.15 K
Human body temperature37°C98.6°F310.15 K
Water boils100°C212°F373.15 K

FAQ

What is the difference between Kelvin and Celsius?

Kelvin and Celsius use the same interval size, but Kelvin starts at absolute zero. K = °C + 273.15.

Why does Fahrenheit use 32 and 212 for water?

On the Fahrenheit scale, water freezes at 32°F and boils at 212°F at standard atmospheric pressure.

Can Kelvin be negative?

Physical Kelvin temperatures cannot be below 0 K. The calculator still shows mathematical conversions for entered values.