How do I convert Celsius to Fahrenheit?

Multiply by 9/5 and add 32: °F = °C × 9/5 + 32. For example 20°C × 9/5 + 32 = 68°F.

What is absolute zero?

Absolute zero is 0 Kelvin = -273.15°C = -459.67°F. It is the lowest possible temperature, where molecular motion is at its minimum.

When do Celsius and Fahrenheit read the same?

At -40 degrees. -40°C equals exactly -40°F — the single point where the two scales intersect.

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, and Rankine. The only everyday conversion that needs an offset, not just a scale factor.

Converters

Celsius °C

Fahrenheit °F

Kelvin K

Rankine °R

About the temperature converter

Temperature is the one common conversion that is affine, not linear: each scale has both a different size of degree AND a different zero point. That is why you cannot just multiply — you scale and then shift. Celsius and Fahrenheit cross at -40°, the one temperature that reads the same on both.

Conversion reference

1 °C	=	1 °C	Celsius
1 °C	=	33.8 °F	Fahrenheit
1 °C	=	274.15 K	Kelvin
1 °C	=	493.47 °R	Rankine

All conversions run entirely in your browser — nothing is sent to a server. Factors are exact wherever an exact definition exists.