Need to convert Fahrenheit to Celsius (°F → °C)? The converter above delivers instant results. Below: the exact formula, a reference table, real-world examples, and the history of both units — everything you need for accurate °F to °C conversion.
The History of the Fahrenheit
Gabriel Daniel Fahrenheit created the first reliable mercury thermometer in 1714. He set 0°F as the coldest temperature he could reproducibly create (a freezing brine of salt, ice, and water) and 96°F as body temperature (later found to be 98.6°F with improved calibration). Fahrenheit's scale was widely adopted in northern Europe and the British Empire. The US is the primary remaining holdout; all US weather, medical references, and cooking still use °F despite decades of metrication efforts.
The History of the Celsius
Anders Celsius proposed his temperature scale in 1742 — but originally with 100° as freezing and 0° as boiling. His colleague Carl Linnaeus reversed it to the intuitive modern form shortly after Celsius's death in 1744. The SI officially defines 0°C = 273.15 K, and 0°C is still (very nearly) the freezing point of pure water at standard pressure. Almost every country except the United States uses Celsius for daily weather, medicine, and cooking.
How to Convert Fahrenheit to Celsius
Subtract 32, then multiply by 5/9.
°C = (°F − 32) × 5/9Step-by-Step Example
- Take your Fahrenheit value — for example, 25 °F.
- Apply the formula: Subtract 32, then multiply by 5/9.
- Result: -3.888889 °C.
Pro Tip: For quick °F to °C conversions without arithmetic, bookmark this page. The interactive tool above updates instantly as you type.
Fahrenheit to Celsius Reference Table
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| -40 °F | -40.0 °C |
| -4 °F | -20.0 °C |
| 32 °F | 0.0 °C |
| 68 °F | 20.0 °C |
| 98.6 °F | 37.0 °C |
| 212 °F | 100.0 °C |
Real-World Examples — °F to °C
- -17.22222 °C — the equivalent of 1 °F (the smallest reference point)
- -12.22222 °C — a practical mid-range value (10 °F)
- 37.77778 °C — a common large-quantity reference (100 °F)
Applications of Fahrenheit-to-Celsius Conversion
The °F to °C conversion is needed in meteorology, medicine, cooking, and material science. Here's where it specifically matters:
- International specifications: Products designed in one unit system must be documented for users who work in the other.
- Scientific and technical work: Research papers and engineering drawings specify temperature in a particular unit — accurate conversion prevents costly errors.
- Education: Physics, chemistry, and applied math curricula require fluency in temperature unit conversion.
- Everyday tasks: Cooking, construction, fitness, and travel all involve temperature conversions when switching between unit systems.
Common Mistakes When Converting Fahrenheit to Celsius
- Mistake: Forgetting to add 32 when converting C→F (a partial formula)
- Mistake: Using the wrong formula direction (multiplying instead of dividing)
- Mistake: Confusing Kelvin with Celsius in scientific calculations
Frequently Asked Questions — Fahrenheit to Celsius
What is the formula for Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. Example: (98.6 − 32) × 5/9 = 37°C.
What is 32°F in Celsius?
32°F = 0°C — the freezing point of water.
What is 72°F in Celsius?
72°F = 22.22222°C — a comfortable room temperature.
What is 100°F in Celsius?
100°F = 37.77778°C — a fever in humans (clinical fever threshold is 100.4°F = 38°C).
At what temperature are Fahrenheit and Celsius equal?
At exactly −40° — this is where both scales intersect.
Is 98.6°F always normal body temperature?
98.6°F (37°C) is the historical average, but normal ranges 97–99°F (36.1–37.2°C) and varies by time of day, measurement method, and individual.
Conclusion
Converting Fahrenheit to Celsius: use the formula °C = (°F − 32) × 5/9. The converter above handles any value instantly. Refer to the table above for quick reference values, and bookmark this page for fast °F to °C access.