Fahrenheit to Celsius Converter (°F to °C)
°C = (°F − 32) × 5/9. Convert Fahrenheit to Celsius for US weather, fever readings and food-safety temperatures, with °F and °C charts.
°C = (°F − 32) × 5/9
Fahrenheit (°F): Fahrenheit temperature is defined by °F = °C × 9/5 + 32. Thus 0 °C equals exactly 32 °F, 100 °C equals exactly 212 °F, and absolute zero is −459.67 °F.
Celsius (°C): Celsius temperature is the kelvin value minus exactly 273.15. At standard atmospheric pressure, pure water freezes near 0 °C and boils near 100 °C; these water temperatures are reference points, not the modern definition of the scale.
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| 1 | -17.2222222222 |
| 5 | -15 |
| 10 | -12.2222222222 |
| 25 | -3.88888888889 |
| 50 | 10 |
| 100 | 37.7777777778 |
Fahrenheit is still the everyday scale in the United States, so a US weather app, fever thermometer, meat thermometer or recipe gives numbers that need converting for anyone used to Celsius. The scales differ in both zero point and degree size: subtract 32 first, then multiply by 5/9. Doing it in the other order is a common mistake and gives a badly wrong answer.
Health and food rules are where the exact figure matters. The CDC treats a measured temperature of 100.4 °F or higher as a fever, which is exactly 38 °C, and US food-safety charts give cooking and storage temperatures in Fahrenheit only. The threshold table below shows each one on the Celsius scale used by thermometers sold almost everywhere else.
How to use this tool
- Type a value in the Fahrenheit box to see it in degrees Celsius, or type in the Celsius box to convert the other way.
- Press ⇄ to swap the two units, or Load example for a typical value.
- Check the charts below for common values; for other units, open the Temperature converter.
Formula
°C = (°F − 32) × 5/9
°F = °C × 9/5 + 32
The scales have different zero points, so the formula adds or subtracts an offset as well as multiplying.
Example
Two conversions worked with the same factors the converter uses:
100.4 °F = 38 °C
21 °C = 69.8 °F
Fahrenheit to Celsius chart
Common values from degrees Fahrenheit to degrees Celsius, rounded to four decimal places.
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| -20 | -28.8889 |
| -4 | -20 |
| 0 | -17.7778 |
| 10 | -12.2222 |
| 14 | -10 |
| 23 | -5 |
| 32 | 0 |
| 40 | 4.4444 |
| 45 | 7.2222 |
| 50 | 10 |
| 59 | 15 |
| 65 | 18.3333 |
| 68 | 20 |
| 72 | 22.2222 |
| 75 | 23.8889 |
| 77 | 25 |
| 80 | 26.6667 |
| 86 | 30 |
| 90 | 32.2222 |
| 95 | 35 |
| 97 | 36.1111 |
| 98.6 | 37 |
| 99.5 | 37.5 |
| 100.4 | 38 |
| 102 | 38.8889 |
| 104 | 40 |
| 110 | 43.3333 |
Celsius to Fahrenheit chart
The reverse direction for values people often look up.
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| -18 | -0.4 |
| -10 | 14 |
| -5 | 23 |
| 0 | 32 |
| 4 | 39.2 |
| 15 | 59 |
| 18 | 64.4 |
| 22 | 71.6 |
| 25 | 77 |
| 28 | 82.4 |
| 33 | 91.4 |
| 36.5 | 97.7 |
| 38 | 100.4 |
| 39 | 102.2 |
| 63 | 145.4 |
| 71 | 159.8 |
| 74 | 165.2 |
Fahrenheit thresholds from US health and food guidance
| Threshold | Fahrenheit (°F) | Celsius (°C) |
|---|---|---|
| Fever, as defined by the CDC (at or above) | 100.4 | 38 |
| Refrigerator, keep at or below | 40 | 4.4444 |
| Freezer, keep at or below | 0 | -17.7778 |
| Steaks, roasts and fish, minimum internal | 145 | 62.7778 |
| Ground beef and pork, minimum internal | 160 | 71.1111 |
| Poultry and leftovers, minimum internal | 165 | 73.8889 |
Quick mental estimate
Take away 30 and halve: 70 °F → 40 ÷ 2 = 20 °C, against an exact 21.1 °C. The shortcut is exact at 50 °F and drifts by about 1 °C for every 18 °F you move away from it, so keep it for weather rather than fevers or cooking.
Use the converter or the charts when the exact figure matters.
The two units
Fahrenheit (°F): Fahrenheit temperature is defined by °F = °C × 9/5 + 32. Thus 0 °C equals exactly 32 °F, 100 °C equals exactly 212 °F, and absolute zero is −459.67 °F.
Celsius (°C): Celsius temperature is the kelvin value minus exactly 273.15. At standard atmospheric pressure, pure water freezes near 0 °C and boils near 100 °C; these water temperatures are reference points, not the modern definition of the scale.
Frequently asked questions
Is 99.5 °F a fever?
Not by the CDC definition, which starts at 100.4 °F (38 °C). 99.5 °F is 37.5 °C, slightly above the traditional 98.6 °F (37 °C) figure, and normal readings vary with the time of day and where the temperature is taken.
What Celsius temperature should a refrigerator be?
US guidance says 40 °F or below, which is about 4.4 °C, and a freezer at 0 °F, about −17.8 °C. UK food-safety guidance asks for a fridge at 5 °C or below.
Why does the US still use Fahrenheit?
Fahrenheit was the usual scale in Britain and its former colonies before the metric era. Most of them moved to Celsius during the 20th century, but the United States kept Fahrenheit for weather, cooking and home thermostats.
How precise is the result?
The converter uses the exact definitions above with browser floating-point arithmetic and shows up to 12 significant digits. The charts round to four decimal places for reading.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/fahrenheit-to-celsius-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Fahrenheit to Celsius Converter (°F to °C). https://kakao.mobile/tools/fahrenheit-to-celsius-converter/
“Fahrenheit to Celsius Converter (°F to °C).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/fahrenheit-to-celsius-converter/.
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