Turn any Fahrenheit reading into Celsius and Kelvin.
Type a temperature in Fahrenheit and watch it convert live to Celsius using C = (F - 32) x 5/9. The Celsius field is editable too, so you can go either way, and Kelvin updates alongside. Handles negatives, below-zero winters and boiling points.
Your temperature
Enter a value in either field. F to C uses C = (F - 32) x 5/9; C to F uses F = C x 9/5 + 32.
What this reading means
Common temperatures
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Fahrenheit and Celsius explained
The Fahrenheit-to-Celsius Formula
To convert Fahrenheit to Celsius: C = (F - 32) × 5/9. First subtract 32 to align the scales at water's freezing point, then multiply by 5/9 (or divide by 1.8) to account for the smaller Fahrenheit degree size. This is the exact inverse of the C → F formula.
When You'll Need This Conversion
US users converting recipes from European cookbooks, travelers reading weather forecasts abroad, scientists working with international data, and anyone reading specifications from non-US sources need F → C conversion. Most thermometers worldwide display Celsius; you may need to translate to your familiar scale.
Reference Temperatures
32 °F = 0 °C (water freezes). 50 °F = 10 °C (cool day). 72 °F = 22.2 °C (typical thermostat). 98.6 °F = 37 °C (body temperature). 100 °F = 37.8 °C (feverish, hot day). 212 °F = 100 °C (water boils at sea level). 350 °F = 177 °C (baking).
Mental Math Shortcut
For quick estimates: subtract 30, divide by 2. For 72 °F: (72-30)/2 = 21 °C (actual 22.2). Accurate within 2-3°C for typical temperatures. Use the calculator for precision.
Common questions
What is 72 °F in Celsius?
72 °F equals about 22.2 °C, a typical indoor thermostat setting in the US.
How cold is 0 °F in Celsius?
0 °F equals -17.8 °C, quite cold, but not as cold as it sounds to Americans. Standard winter low in northern US states.
What is freezing temperature in both scales?
Water freezes at 0 °C = 32 °F at standard atmospheric pressure. Saltwater and saline solutions freeze at lower temperatures.
Why divide by 1.8?
Each Fahrenheit degree is 1.8 times smaller than each Celsius degree. After shifting by 32 (so both scales start at water's freezing point), dividing by 1.8 corrects for the size difference.
Is the formula exact?
Yes, C = (F - 32) × 5/9 is exact. 5/9 is precise (not 0.555..., it is exactly 5÷9). Calculators round to several decimals but the relationship is exact.
All conversion runs in your browser. Nothing is uploaded. Fahrenheit, Celsius and Kelvin describe the same temperature in different scales. The single point where Fahrenheit and Celsius meet is -40, the same number in both.