What this does
Converts Fahrenheit to Celsius as you type. The formula is °C = (°F − 32) × 5/9: take away the 32-degree offset first, then divide by 1.8. The page opens at 70 °F — a US thermostat setting — and shows 21.111111 °C. Both fields are live; edit either one and the other recomputes on every keystroke. The ⇄ button swaps the two scales and keeps the left-hand number. Everything runs in the browser, so it works offline.
How do I convert Fahrenheit to Celsius by hand?
Subtract 32, multiply by 5, divide by 9. For 50 °F: 50 − 32 = 18, × 5 = 90, ÷ 9 = 10 °C. The order matters — subtract before you scale. A common mistake is dividing by 1.8 first and then subtracting 32, which gives nonsense (50 ÷ 1.8 − 32 = −4). If you only remember the other direction, °F = °C × 9/5 + 32, just undo it step by step: undo the +32, then undo the ×9/5.
Fahrenheit to Celsius at a glance
| °F | °C | Where you'll meet it |
|---|---|---|
| 0 | −17.777778 | a cold Minnesota morning |
| 32 | 0 | freezing; the offset itself |
| 60 | 15.555556 | US weather "mild" |
| 72 | 22.222222 | office air-conditioning |
| 90 | 32.222222 | a hot US summer day |
| 101 | 38.333333 | a fever on a US thermometer |
| 350 | 176.666667 | the default US baking temperature |
| 425 | 218.333333 | roasting vegetables |
Is there a quick approximation?
Subtract 32, halve it, then add a tenth of what you've got. For 70 °F: 38 → 19 → 21. For 90 °F: 58 → 29 → 32. That's accurate to within a degree across the whole weather range. The rougher "subtract 30, halve" version (70 → 20) is fine for deciding on a jacket but drifts to 3–4 degrees off at the hot end.
What is 350 °F in Celsius for a recipe?
176.666667 °C by the formula, which no oven dial has. Round to the nearest oven notch: 350 °F → 180 °C, 325 °F → 160 °C, 375 °F → 190 °C, 400 °F → 200 °C, 425 °F → 220 °C, 450 °F → 230 °C. If yours is a fan (convection) oven, take a further 20 °C off. For internal meat temperatures use the exact figure — 165 °F for poultry is 73.888889 °C, so aim for 74 °C.
Why does the tool show 21.111111 instead of 21.1?
Because 70 − 32 = 38, and 38 ÷ 1.8 = 21.1111… repeating. The tool rounds to six decimal places and shows every one of them rather than guessing how much precision you want. Any Fahrenheit value that isn't a multiple of 9 above 32 produces a repeating decimal in Celsius, so you'll see six digits often. For weather, keep one decimal or none; for a fever, one decimal (38.3 °C for 101 °F); for a lab or a sous-vide bath, keep what the tool gives you.
Can I go back to Fahrenheit, or use Kelvin?
Type into the right-hand (Celsius) box and the Fahrenheit side recomputes, or press ⇄ to swap the scales. Kelvin is in both dropdowns — 70 °F is 294.261111 K — because this page hides the category tabs but keeps all three temperature units. The Celsius to Fahrenheit page covers the other direction with oven and fever tables the metric way round, and the full unit converter handles everything else.