Fahrenheit is a temperature scale with water freezing at 32 F and boiling at 212 F.
Fahrenheit to Celsius Converter — F to C
Convert Fahrenheit (F) to Celsius (C) using the exact temperature formula. See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Fahrenheit to Celsius converter
Converter
Temperature Converter
Convert Celsius, Fahrenheit, Kelvin, Rankine, Delisle, Newton, Reaumur, and Romer.
Context values
Some unit families need one extra value for a physically accurate result.
Celsius is a temperature scale with water freezing at 0 C and boiling at 100 C.
Convert the source temperature to Kelvin, then convert Kelvin to the target scale.
Temperature conversion uses Kelvin as the intermediate absolute scale.
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About Converting Fahrenheit to Celsius
Fahrenheit and Celsius are the two everyday temperature scales, and converting between them matters for reading weather forecasts, following recipes, and understanding scientific data across regions. Fahrenheit is typically associated with united States (primary everyday temperature scale), while Celsius is typically associated with standard temperature scale in nearly every country except the United States.
Formula
°C = (°F − 32) × 5/9
This is the inverse of the Celsius-to-Fahrenheit formula: first remove Fahrenheit's 32-degree offset, then rescale the 180-degree Fahrenheit span down to Celsius's 100-degree span.
Simple example
(0 − 32) × 5/9 = -17.77777778 °C
0 fahrenheit = -17.77777778 celsius.
Real-world example
(0 − 32) × 5/9 = -17.77777778 °C
0 fahrenheit = -17.77777778 celsius.
Conversion table
| Fahrenheit (F) | Celsius (C) |
|---|---|
| -40 F | -40 C |
| -20 F | -28.88888889 C |
| 0 F | -17.77777778 C |
| 20 F | -6.666666667 C |
| 37 F | 2.777777778 C |
| 100 F | 37.77777778 C |
Reverse conversion: Celsius to Fahrenheit
(-17.22222222 × 9/5) + 32 = 1.000000004 °F
-17.22222222 celsius = 1.000000004 fahrenheit.
°F = (°C × 9/5) + 32
For a page dedicated to this direction, see Celsius to Fahrenheit.
Fahrenheit vs. Celsius
| Aspect | Fahrenheit | Celsius |
|---|---|---|
| Family | Non-SI temperature scale | SI-derived temperature scale |
| Typical use | Everyday weather reporting and thermostats in the US | Weather forecasting and climate reporting worldwide |
| Where it's used | United States (primary everyday temperature scale) | Standard temperature scale in nearly every country except the United States |
Understanding the Fahrenheit
Fahrenheit (F) measures temperature. Fahrenheit sets water's freezing point at 32 °F and boiling point at 212 °F at standard atmospheric pressure. It is classified as a Non-SI temperature scale.
Where it's used: United States (primary everyday temperature scale) A small number of other territories, e.g. the Bahamas, Belize, Cayman Islands, Liberia, Palau
Uses of the Fahrenheit today
- Everyday weather reporting and thermostats in the US
- Cooking temperatures in US recipes
- Some US industrial and HVAC contexts
History of the Fahrenheit
German physicist Daniel Gabriel Fahrenheit developed the scale around 1724, originally basing 0° on the coldest temperature he could reliably reproduce with an ice-salt mixture, and calibrating other points using human body temperature and the freezing point of water.
The modern Fahrenheit scale was later standardized so that water freezes at exactly 32 °F and boils at exactly 212 °F at one standard atmosphere, giving 180 degrees between the two reference points.
Historical origin. Fahrenheit was not the invention of a single named person; it developed through the process described above.
Understanding the Celsius
Celsius (C) measures temperature. Celsius is defined relative to the Kelvin scale, with 0 °C set at 273.15 K. It is classified as a SI-derived temperature scale.
Where it's used: Standard temperature scale in nearly every country except the United States
Uses of the Celsius today
- Weather forecasting and climate reporting worldwide
- Scientific and laboratory temperature measurement (alongside Kelvin)
- Cooking and food safety in most countries outside the US
History of the Celsius
Swedish astronomer Anders Celsius proposed a 100-point temperature scale in 1742, but his original scale ran in the opposite direction, with 0° at water's boiling point and 100° at freezing.
The scale was reversed to its modern orientation shortly after his death, commonly attributed to instrument maker Daniel Ekström and naturalist Carl Linnaeus around 1744-1745.
The scale was renamed from 'centigrade' to 'Celsius' by international agreement in 1948, and it is now formally defined as the Kelvin scale shifted by 273.15, rather than independently by the freezing and boiling points of water.
Historical origin. Celsius was not the invention of a single named person; it developed through the process described above.
Fahrenheit — sources
- NIST — Temperature scales overview — History and modern definitions of Fahrenheit and Celsius.
Celsius — sources
- BIPM SI Brochure — Celsius temperature scale — Formal definition tying Celsius to Kelvin.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many celsius are in 1 fahrenheit?
1 fahrenheit equals -17.22222222 celsius, using the offset temperature formula rather than an estimate.
How do I convert fahrenheit to celsius?
Use the formula shown above: it involves both a multiplication and an addition/subtraction because the two scales don't share a common zero point.
How do I convert celsius back to fahrenheit?
Use the reverse factor: 1 celsius equals 33.8 fahrenheit. You can also use the swap control in the converter above to flip the direction instantly.
What is a fahrenheit?
Fahrenheit (F) measures temperature. Fahrenheit sets water's freezing point at 32 °F and boiling point at 212 °F at standard atmospheric pressure. It is classified as a Non-SI temperature scale.
What is a celsius?
Celsius (C) measures temperature. Celsius is defined relative to the Kelvin scale, with 0 °C set at 273.15 K. It is classified as a SI-derived temperature scale.
Is the Fahrenheit to Celsius conversion exact?
Yes. Both scales are formally defined relative to the Kelvin scale, so the conversion formula is exact — the only rounding involved is in how many decimal places you choose to display.
Where is the fahrenheit still used today?
United States (primary everyday temperature scale) A small number of other territories, e.g. the Bahamas, Belize, Cayman Islands, Liberia, Palau