Converters
Fahrenheit to Celsius
The formula is (°F − 32) × 5/9. Subtract 32, then multiply by 0.5556. Below: the formula explained, a rough mental math shortcut, and a full reference chart.
The formula
°C = (°F − 32) × 5/9
Or equivalently: °C = (°F − 32) × 0.5556
The −32 corrects for the different zero points (water freezes at 0°C but 32°F). The × 5/9 corrects for the different step sizes — a degree of Fahrenheit is smaller than a degree of Celsius, so you need the 5/9 factor to scale back down.
Three worked examples
32°F→0°CWater's freezing point72°F→22.2°CComfortable indoor temperature212°F→100°CWater's boiling pointMental math shortcut
For a rough estimate without a calculator: subtract 30, then divide by 2.
86°F → subtract 30 = 56 → divide by 2 = ~28°C (actual: 30°C)
68°F → subtract 30 = 38 → divide by 2 = ~19°C (actual: 20°C)
This is an approximation — it's off by 1–2°C depending on the temperature. Good enough to know whether to pack a jacket. For precision, use the formula or the converter above.
When you need this conversion
You're looking at a US weather app and it says 104°F. Is that dangerous? Yes — that's 40°C. Heatstroke territory. Meanwhile, 68°F sounds fine — and it is, that's 20°C, a comfortable room.
US recipes often give oven temperatures in Fahrenheit. If a recipe says 350°F and your oven is in Celsius, that's about 177°C — call it 180°C. If it says 425°F, that's 218°C, call it 220°C.
In medicine: if a US thermometer reads 101°F, that's 38.3°C. A clear fever. If it reads 98°F, that's 36.7°C — slightly below normal, but fine.
Fahrenheit to Celsius chart
| °F | °C | Context |
|---|---|---|
| -40 | -40 | Scales intersect |
| 0 | -17.78 | Very cold |
| 32 | 0 | Water freezes |
| 50 | 10 | Chilly |
| 60 | 15.56 | Cool day |
| 68 | 20 | Comfortable room |
| 77 | 25 | Warm day |
| 86 | 30 | Hot summer day |
| 98.6 | 37 | Body temperature |
| 104 | 40 | Fever / dangerous heat |
| 212 | 100 | Water boils |
| 350 | 176.67 | Moderate oven |
| 425 | 218.33 | Hot oven |
Convert any temperature instantly
Type in Fahrenheit, Celsius, or Kelvin — all three update as you type.
Temperature Converter →Frequently asked questions
What is the formula to convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9 (or 0.5556). Written out: °C = (°F − 32) × 5/9. For example, 98.6°F = (98.6 − 32) × 5/9 = 66.6 × 0.5556 = 37°C.
What is 98.6°F in Celsius?
98.6°F is 37°C — normal human body temperature. The calculation: (98.6 − 32) × 5/9 = 66.6 × 5/9 = 37°C exactly.
What is 72°F in Celsius?
72°F is approximately 22.2°C. The calculation: (72 − 32) × 5/9 = 40 × 5/9 = 22.22°C. This is a classic comfortable room temperature.
Is there a quick mental math shortcut for Fahrenheit to Celsius?
Yes. Subtract 30, then divide by 2. This gives a rough estimate within a couple of degrees for most everyday temperatures. For 86°F: subtract 30 = 56, divide by 2 = 28°C. The actual answer is 30°C — close enough to know it's a hot day.
What is 32°F in Celsius?
32°F is 0°C — the freezing point of water. The calculation: (32 − 32) × 5/9 = 0 × 5/9 = 0°C.
Why does the US use Fahrenheit instead of Celsius?
The US adopted Fahrenheit in colonial times and never switched to metric like most other countries did in the 20th century. Fahrenheit was calibrated so that 0°F was the coldest temperature Daniel Fahrenheit could achieve with a brine-ice mixture, and 96°F approximated human body temperature. Today, Fahrenheit is mainly used in the US, the Bahamas, and a few other countries for everyday temperature. Scientists everywhere use Celsius or Kelvin.