Celsius to Fahrenheit and Back: The Easy Conversion Method

Whether you're following a US recipe, reading a fever, or doing physics homework, temperature conversion comes up constantly. Here's the exact method and a mental shortcut.

The exact formulas

°F to °C: subtract 32, multiply by 5/9. °C to °F: multiply by 9/5, add 32. The temperature converter handles Celsius, Fahrenheit and Kelvin instantly so you never have to do it by hand.

The mental shortcut

For a rough °C to °F: double the Celsius and add 30. 20°C → roughly 70°F (exact is 68). It's close enough for weather and cooking, off by a few degrees at extremes.

The anchors worth memorizing

0°C = 32°F (freezing). 37°C = 98.6°F (body temperature). 100°C = 212°F (boiling). 180°C = 356°F (common baking temperature). Kelvin = Celsius + 273.15 (absolute zero is 0 K = −273.15°C).

Where conversions trip people up

A fever of 100°F sounds alarming but is 37.8°C — barely elevated. An oven at 350°F is 177°C. Knowing the anchors prevents over- or under-reacting to unfamiliar units.

More converters

Need other units? Try the length, weight and speed converters — all free.