Temperature Converter - Celsius to Fahrenheit, Kelvin
Convert between Celsius, Fahrenheit, and Kelvin. Temperature uses offset formulas rather than simple multiplication. Enter a value in the calculator below, or browse common values and formulas further down.
Temperature is the only common unit conversion that uses offset formulas rather than simple multiplication. This is because Celsius, Fahrenheit, and Kelvin have different zero points. Water freezes at 0°C (32°F) and boils at 100°C (212°F). Kelvin starts at absolute zero (-273.15°C).
Unlike other unit conversions that use simple multiplication, temperature requires offset formulas because the scales have different zero points. Here are the three most common conversions:
°F = °C × 9/5 + 32
°C = (°F - 32) × 5/9
K = °C + 273.15
For example, to convert 100°C to Fahrenheit: 100 × 9/5 + 32 = 212°F. See the Celsius to Fahrenheit formula for a full step-by-step walkthrough.
Most unit conversions are simple multiplication because the scales share a zero point. Temperature scales have different zero points (0 degrees C = 32 degrees F), so the formulas require both multiplication and addition/subtraction.
Absolute zero is 0 K (Kelvin), which equals -273.15 degrees C or -459.67 degrees F. It is the lowest possible temperature, where molecular motion effectively stops. The Kelvin scale starts at absolute zero, which is why it has no negative values.
-40 is the same in both Celsius and Fahrenheit. This is the only point where the two scales intersect. See the -40 degrees C to F conversion.
Water freezes at 0 degrees C (32 degrees F) and boils at 100 degrees C (212 degrees F). Normal body temperature is about 37 degrees C (98.6 degrees F). Room temperature is roughly 20-22 degrees C (68-72 degrees F).
