Temperature Converter

How to convert temperature

Temperature is the one non-linear scale here: each scale has a different zero, so you add or subtract an offset as well as scaling. The core formulas are °F = °C × 9/5 + 32, °C = (°F − 32) × 5/9, and K = °C + 273.15. Rankine relates to Fahrenheit the way Kelvin relates to Celsius: °R = °F + 459.67.

Worked example

To convert 100 °C to Fahrenheit: 100 × 9/5 + 32 = 212 °F. To convert normal body temperature, 98.6 °F, to Celsius: (98.6 − 32) × 5/9 = 37 °C.

When you'll use a temperature converter

Temperature conversion is everyday for weather (Celsius versus Fahrenheit), cooking and oven settings, travel between metric and US regions, and science or engineering work in Kelvin. Because the scales have different zeros, 0 in one is never 0 in another - which is exactly why a converter helps.

Frequently asked questions

What is 100 degrees Fahrenheit in Celsius?

100 °F equals about 37.78 °C. Subtract 32 to get 68, then multiply by 5/9: 68 × 5/9 = 37.78 °C.

Why is Kelvin written without a degree symbol?

Kelvin is an absolute thermodynamic scale and an SI base unit, so its values are written as plain numbers followed by K, such as 300 K, rather than degrees. Celsius, Fahrenheit, and Rankine all keep the degree symbol.

Is a temperature change of one Kelvin the same size as one degree Celsius?

Yes. A change of 1 K is exactly equal to a change of 1 °C, because the two scales share the same step size and differ only by an offset of 273.15. A 1 °F change, by contrast, equals only 5/9 of a Kelvin.

What is the Rankine scale and how does it relate to Fahrenheit?

Rankine is an absolute scale that starts at absolute zero but uses Fahrenheit-sized degrees, so one Rankine degree equals one Fahrenheit degree. To convert, add 459.67 to a Fahrenheit value: °R = °F + 459.67.

How do I set an oven from Fahrenheit to Celsius for 350 °F?

350 °F is about 176.67 °C, which most recipes round to 175 °C or 180 °C. Use (350 − 32) × 5/9 = 176.67 °C.

What is comfortable room temperature in Fahrenheit and Kelvin?

Room temperature of 20 °C is 68 °F and 293.15 K. Add 273.15 to the Celsius value for Kelvin, and use °C × 9/5 + 32 for Fahrenheit.