Use this free fahrenheit to celsius converter to change temperatures in both directions in seconds. It is a two-way temperature converter: choose Fahrenheit to Celsius or Celsius to Fahrenheit, enter one temperature, and the converter shows the result in both scales, plus Kelvin, instantly — no sign-up, no account, and no personal information needed. Your numbers are calculated in your browser and are not sent to us.
Contents: Formula · How to use · Examples · Tips · FAQ · Related tools
No sign-up required. This fahrenheit to celsius converter works in your browser, so the temperature you enter is not stored or sent to us. It is useful for weather, cooking, science, and travel in the United States, the United Kingdom, and Canada.
Fahrenheit to Celsius Formula
The two scales use different zero points and different degree sizes. Fahrenheit sets the freezing point of water at 32 degrees, while Celsius sets it at 0 degrees. A Celsius degree is larger: 100 Celsius degrees cover the same range as 180 Fahrenheit degrees, so the ratio is 5 to 9.
Celsius = (Fahrenheit − 32) × 5 ÷ 9
Fahrenheit = (Celsius × 9 ÷ 5) + 32
Kelvin = Celsius + 273.15
For example, 68°F becomes (68 − 32) × 5 ÷ 9 = 36 × 5 ÷ 9 = 20°C. In the other direction, 20°C becomes (20 × 9 ÷ 5) + 32 = 36 + 32 = 68°F. The fahrenheit to celsius converter does both calculations, so you never need to remember which direction uses subtraction first.
How to Use the Fahrenheit to Celsius Converter
Choose Fahrenheit to Celsius or Celsius to Fahrenheit from the first box, type the temperature into the second box, and tap Convert Temperature. The fahrenheit to celsius converter shows the result in Fahrenheit, Celsius, and Kelvin, so you can check it against a weather report, a recipe, or a scientific reference.
Use Fahrenheit to Celsius for United States weather, ovens, and body temperature, and Celsius to Fahrenheit when you read a forecast, recipe, or instruction from the United Kingdom, Canada, or most other countries. Negative temperatures work too: for example, −40 is the same on both scales, which is a useful check that the formula is correct.
Fahrenheit to Celsius Examples
Example 1 — Convert 68°F to Celsius. (68 − 32) × 5 ÷ 9 = 20°C. This is a comfortable room temperature.
Example 2 — Convert 212°F to Celsius. (212 − 32) × 5 ÷ 9 = 100°C, the boiling point of water at sea level.
Example 3 — Convert 37°C to Fahrenheit. (37 × 9 ÷ 5) + 32 = 98.6°F, normal human body temperature. This reverse example shows that this fahrenheit to celsius page is a true two-way converter, not a single-value page.
Other useful checks: 32°F = 0°C, the freezing point of water; 100°F = 37.8°C, a hot summer day; and 0°C = 32°F.
Fahrenheit to Celsius Tips
For a quick estimate, subtract 30 from the Fahrenheit value and halve the result: 68°F gives about 19°C, close to the exact 20°C. Do not use that estimate for medicine, cooking, or science, where the exact fahrenheit to celsius formula matters. For background on the scales, see Wikipedia’s article on Fahrenheit. Remember that oven temperatures, weather forecasts, and medical readings are often rounded, so a result of 20.0°C and 20°C mean the same thing.
Fahrenheit to Celsius FAQ
What is the fahrenheit to celsius formula? Celsius = (Fahrenheit − 32) × 5 ÷ 9. For example, 68°F = 20°C.
Can this page also convert Celsius to Fahrenheit? Yes. Choose Celsius to Fahrenheit, enter a Celsius temperature, and the converter uses Fahrenheit = (Celsius × 9 ÷ 5) + 32.
What is 100°F in Celsius? It is 37.8°C. (100 − 32) × 5 ÷ 9 = 37.8°C.
What is 0°C in Fahrenheit? It is 32°F, the freezing point of water.
At what temperature are Fahrenheit and Celsius the same? At −40. Both −40°F and −40°C describe the same temperature.
How do I get Kelvin from a Celsius result? Add 273.15 to the Celsius temperature. For example, 20°C + 273.15 = 293.15 K, which is the Kelvin value this converter also shows.
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