Convert Fahrenheit to Celsius

The formula

°C = (°F − 32) × 5/9

Fahrenheit to Celsius — quick reference

American numbers carry their own anchors, and one is already a conversion

Water freezes at 32 °F and boils at 212 °F, so the span a Celsius reader knows as a hundred degrees is a hundred and eighty in Fahrenheit. The Fahrenheit degree is the finer step, which is why American forecasts are quoted in whole numbers without losing much. Weather in the seventies is 21–26 °C and mild; a hundred-degree day is 37.8 °C and genuinely hot.

Medical figures need more care. The American fever threshold of 100.4 °F looks arbitrary until it is converted: it is exactly 38 °C, and the decimal exists only because the number crossed scales. The familiar 98.6 °F is likewise 37 °C rounded, from a measurement made to nothing like that precision.

American oven settings belong on the European ladder, not on a calculator

350 °F is 176.7 °C, a figure no dial offers and no recipe intends. It means the standard moderate oven, which is 180 °C in Europe and gas mark 4. The rest of the ladder behaves the same way: 325 °F is 160–170 °C, 375 °F is 190, 400 °F is 200 and 425 °F is 220. Converting precisely and setting 177 misreads what the recipe is asking for.

American recipes also assume a conventional oven. US ranges distinguish bake from convection bake, and a plain instruction means the first, so a fan oven should sit roughly 20 °C below the converted figure — 160 °C for a 350 °F recipe. Timing matters more than temperature at that point, since fan ovens cook faster as well as more evenly, so start checking early.

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