Convert Fahrenheit to Celsius (°F°C)

Fahrenheit is the everyday temperature scale in the United States, used for weather, cooking, and body temperature.

-17.222222
1 °F-17.222222 °CNIST · BIPM accuracy

Fahrenheit to Celsius Conversion Table

10 common values
FahrenheitCelsius
-40 °F-40 °C
-20 °F-28.888889 °C
0 °F-17.777778 °C
10 °F-12.222222 °C
20 °F-6.666667 °C
25 °F-3.888889 °C
30 °F-1.111111 °C
37 °F2.777778 °C
100 °F37.777778 °C
200 °F93.333333 °C

How to Convert Fahrenheit to Celsius Manually

Step by Step

Temperature scales differ in both zero-point and degree size, so conversion uses a formula — not simple multiplication. Follow these steps to convert degrees Fahrenheit to degrees Celsius by hand.

  1. 1
    Take your value in degrees Fahrenheit
    Start with the number of degrees Fahrenheit (°F) you want to convert.
  2. 2
    Apply the formula
    Use the formula: °C = (°F − 32) × 5/9
  3. 3
    Read the result in degrees Celsius
    The result is your value in degrees Celsius (°C).
Practical Examples
1 °F
equals
-17.222222 °C
5 °F
equals
-15 °C
10 °F
equals
-12.222222 °C
25 °F
equals
-3.888889 °C
100 °F
equals
37.777778 °C

Formula

Temperature conversion uses an offset formula, not simple multiplication.

Forward°C = (°F − 32) × 5/9
Reverse°F = (°C × 9/5) + 32

Tips

Use these in everyday conversions
  • Formula: °F = (°C × 9/5) + 32.
  • Rough conversion: subtract 30 then halve to get °C. 70 °F → 20 °C.
  • US ovens in °F; European ovens in °C. Convert before starting a foreign recipe.

Common Mistakes

Avoid these
  • Using °F readings in European contexts without conversion.
  • Forgetting the +32 offset — a 20 °F rise is not 20 °C rise.
  • Assuming 50 °F is half of 100 °F in feel — in °C it is 10 °C vs. 38 °C.

About Fahrenheit and Celsius

What is the Fahrenheit?

Fahrenheit is the everyday temperature scale in the United States, used for weather, cooking, body temperature, and HVAC settings. Proposed by German physicist Daniel Gabriel Fahrenheit in 1724, it set 0°F as the lowest temperature he could reliably reproduce (a brine-ice mixture) and 96°F as human body temperature. Modern definitions place water's freezing point at exactly 32°F and boiling at 212°F — making the freezing-to-boiling range exactly 180 degrees. The Fahrenheit scale was the international standard for English-speaking countries until the UK and Commonwealth nations switched to Celsius in the 1960s and 70s. Today the United States is the only major industrialized country still using Fahrenheit for weather. A comfortable room is 68–72°F, fever begins at 100.4°F, and Death Valley summer highs reach 120°F. Fahrenheit relates to Celsius by °C = (°F − 32) × 5/9.

  • US daily weather and climate reports
  • US cooking oven temperatures
  • US medical thermometers
Real-world examples

US room temperature 68–72 °F. Body temperature 98.6 °F. Fever 100.4 °F. Pizza oven 450 °F.

What is the Celsius?

Celsius is the global temperature scale used for weather forecasts, science, medicine, and daily life in all countries except the United States. Originally proposed by Swedish astronomer Anders Celsius in 1742 (with 0° as boiling and 100° as freezing — the inverse of today's scale), the modern version was reversed shortly after his death. Since 2019, Celsius has been redefined via the Kelvin scale: 0°C is exactly 273.15 K, and 1°C equals 1 K in size. Water freezes at 0°C, boils at 100°C at sea level, and human body temperature is around 37°C. Comfortable room temperature is about 20–22°C, and a hot summer day is 30–35°C. Celsius relates to Fahrenheit by the formula °F = °C × 9/5 + 32, and to Kelvin by adding 273.15. The scale's decimal-friendly division of water's phase transitions made it the natural metric choice.

  • Daily weather forecasts worldwide (except US)
  • Cooking temperatures in Europe, Asia, Latin America
  • Body temperature on medical thermometers
Real-world examples

Room temperature is about 20 °C. Normal body temperature is 37 °C. Typical fridge setting is 4 °C. European winter can reach −20 °C; desert summer 45+ °C.

Learn About Both Units

🌡️ Reference

What is the Fahrenheit?

Read the unit page →
🌡️ Reference

What is the Celsius?

Read the unit page →

Fahrenheit to Celsius FAQ

5 questions
How many degrees Celsius in a fahrenheit?
One fahrenheit equals -17.222222 degrees Celsius.
How do I convert degrees Fahrenheit to degrees Celsius?
Temperature conversion is non-linear. From Fahrenheit to Celsius use the specific formula — this tool applies it automatically.
What is 100 degrees Fahrenheit in degrees Celsius?
100 degrees Fahrenheit equals 37.777778 degrees Celsius.
Is a fahrenheit bigger than a celsius?
Temperature units compare by scale, not by size of one degree. Fahrenheit and Celsius use different zero points.
How to convert degrees Fahrenheit to degrees Celsius without a calculator?
Use the mental shortcut relevant to these temperature scales — but for accuracy always verify with a calculator.

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