Celsius to Fahrenheit and Fahrenheit to Celsius

degrees Celsius to degrees Fahrenheit formula

°F = °C × 1.8 + 32

Take the degrees Celsius figure and multiply by 1.8, then add 32.

degrees Celsius to degrees Fahrenheit table

Common degrees Celsius to degrees Fahrenheit conversions

0 °C = 32 °F. 0 degrees Celsius is 32 degrees Fahrenheit.

20 °C = 68 °F. 20 degrees Celsius is 68 degrees Fahrenheit.

37 °C = 98.6 °F. 37 degrees Celsius is 98.6 degrees Fahrenheit.

100 °C = 212 °F. 100 degrees Celsius is 212 degrees Fahrenheit.

180 °C = 356 °F. 180 degrees Celsius is 356 degrees Fahrenheit.

degrees Fahrenheit to degrees Celsius formula

°C = (°F − 32) ÷ 1.8

Take the degrees Fahrenheit figure and subtract 32, then divide by 1.8.

degrees Fahrenheit to degrees Celsius table

Common degrees Fahrenheit to degrees Celsius conversions

32 °F = 0 °C. 32 degrees Fahrenheit is 0 degrees Celsius.

68 °F = 20 °C. 68 degrees Fahrenheit is 20 degrees Celsius.

98.6 °F = 37 °C. 98.6 degrees Fahrenheit is 37 degrees Celsius.

212 °F = 100 °C. 212 degrees Fahrenheit is 100 degrees Celsius.

350 °F = 176.667 °C. 350 degrees Fahrenheit is 176.667 degrees Celsius.

How the Celsius To Fahrenheit works

Celsius to Fahrenheit: why there is a plus 32

Celsius puts the freezing point of water at 0 and boiling at 100. Fahrenheit puts them at 32 and 212. So a Fahrenheit degree is 100/180 of a Celsius degree — each Celsius degree is 1.8 Fahrenheit degrees — and the zero points are 32 apart. Multiply by 1.8 to fix the size of the degree, then add 32 to fix the zero. Because of the offset, you cannot convert a temperature difference by the same formula: a rise of 10 °C is a rise of 18 °F, not 50 °F.

Worked example: 37 °C body temperature

37 × 1.8 = 66.6; plus 32 = 98.6 °F. That is the textbook normal body temperature in both systems. A fever of 38.5 °C is 101.3 °F, and 40 °C is 104 °F. Thermometers sold in the US read in Fahrenheit and in most of the rest of the world in Celsius; a reading of 39 on one is a serious fever and on the other a broken thermometer.

Worked example: a 180 °C oven

180 × 1.8 = 324; plus 32 = 356 °F. American recipes give 350 °F for the same setting, which is 177 °C — the difference is well within an oven's accuracy. The common steps line up like this: 160 °C is 320 °F, 180 °C is 356 °F (350), 200 °C is 392 °F (400), 220 °C is 428 °F (425). Fan ovens are usually set 20 °C lower, which is 36 °F.

Weather

The figures people want most: 0 °C is 32 °F, freezing. 10 °C is 50 °F, a cool day. 20 °C is 68 °F, room temperature. 25 °C is 77 °F, warm. 30 °C is 86 °F, hot. 35 °C is 95 °F, a heatwave. 40 °C is 104 °F. Below zero, −10 °C is 14 °F and −20 °C is −4 °F. The two scales give the same number at −40, and only there.

In your head

Double it and add 30. 20 °C: 40 + 30 = 70, against the exact 68. It is exact at 10 °C and drifts by one degree for every 5 °C away from that, so it is fine for weather and useless for ovens. For cooking temperatures, double it, take off ten percent and add 32: 180 → 360 − 36 + 32 = 356, exact.

Kelvin

Scientific work uses kelvin, which has the same degree size as Celsius but starts at absolute zero: K = °C + 273.15. So 20 °C is 293.15 K and 68 °F. The Celsius-to-kelvin page handles that; Fahrenheit's counterpart, the Rankine scale, is rarely used outside American engineering.

Worked example: 72 °F room temperature

72 − 32 = 40; 40 ÷ 1.8 = 22.2 °C. American thermostats default to around 72 °F in winter and 78 °F (25.6 °C) in summer; European ones to 20 or 21 °C, which is 68 to 70 °F. A thermostat set to 65 °F is 18.3 °C, the figure health advice uses as a minimum for living rooms.

Worked example: a 101 °F fever

101 − 32 = 69; 69 ÷ 1.8 = 38.3 °C. Normal is 98.6 °F, which is 37.0 °C exactly (the Fahrenheit figure is the conversion of a rounded Celsius one, not the other way round). Fever is usually taken to start at 100.4 °F, which is 38.0 °C, and 104 °F is 40 °C. If a reading looks impossible — 39 or 100 — check which scale the thermometer is on.

Celsius to Fahrenheit formula and table

The formula on this page is °F = °C × 1.8 + 32, applied exactly before rounding for display.

How many degrees Fahrenheit in 0 degrees Celsius? 0 °C is 32 °F. Likewise 20 °C is 68 °F, 37 °C is 98.6 °F, 100 °C is 212 °F.

Celsius to Fahrenheit conversion table

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