Fahrenheit to Celsius
This free Fahrenheit to Celsius converter is the direction most of the world needs when meeting American numbers: a 75 °F weather forecast, an oven preheated to 350 °F, a fever of 100.4 °F, a freezer at 0 °F.
How to use
- Type a temperature in degrees Fahrenheit into the Value box.
- The Celsius equivalent appears instantly as you type.
- Swap the From and To selects to convert Celsius back to Fahrenheit.
- Copy the full equation shown under the result into your notes or recipe.
Frequently asked questions
What is the formula for Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. For example, (98.6 − 32) × 5/9 = 37 °C exactly. Subtracting 32 removes Fahrenheit’s offset before the 5/9 scale factor is applied, which is why the order of operations matters.
What is 100 degrees Fahrenheit in Celsius?
(100 − 32) × 5/9 = 37.77777778 °C — a common fever-threshold figure in US health advice. Body-normal 98.6 °F is exactly 37 °C.
Why do I subtract 32 before multiplying?
Because the two scales differ in both size and origin: a Fahrenheit degree is 5/9 of a Celsius degree, but Fahrenheit’s zero sits 32 degrees below water’s freezing point. The offset must be removed first, then the sizes rescaled — reversing the order gives a wrong answer.
Do you store the temperatures I convert?
No. The conversion runs entirely in your browser and nothing is uploaded, stored or logged. Close the page and nothing remains.
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About this tool
This free Fahrenheit to Celsius converter is the direction most of the world needs when meeting American numbers: a 75 °F weather forecast, an oven preheated to 350 °F, a fever of 100.4 °F, a freezer at 0 °F. Temperature scales cannot be converted by a multiplication factor alone because their zero points differ, so this page uses the real offset formula — °C = (°F − 32) × 5/9 — and applies it exactly: 32 °F becomes 0 °C, 98.6 °F becomes exactly 37 °C, 212 °F becomes 100 °C. Results update on every keystroke and the full equation appears underneath, ready for a recipe card, a medical note or homework. Anchors that make the foreign scale familiar: 68 °F is room temperature at 20 °C, 350 °F — the most common US baking temperature — is 176.6666667 °C, 0 °F is a hard freezer at about −17.78 °C, and −40 is where both scales meet. Because everything runs locally in your browser, the readings you enter are never uploaded, stored or logged — a sensible default for health data about you or your family. To convert Celsius back to Fahrenheit, swap the From and To selects and the page flips direction in one click.