Convert Celsius to Fahrenheit (°C to °F)

This direction is for when you already have a temperature in Celsius — a metric oven dial, a local weather reading, a thermometer — and need to express it in Fahrenheit for a US recipe, a US-based reader, or a form that expects Fahrenheit.

Adapting a European recipe for a US oven is the most common trigger: a recipe calling for 180 °C converts to 356 °F, which most people round to the nearest common oven setting, 350 °F. Because the scales are offset rather than proportional, you can't just scale the number — 180 °C is not "180-ish" in Fahrenheit, and rounding the Celsius figure before converting compounds the error.

Describing weather to someone who thinks in Fahrenheit is another everyday case: a mild 20 °C day is 68 °F, and a hot 35 °C day is 95 °F. These numbers don't track proportionally either — a temperature twice as high in Celsius is not twice as high in Fahrenheit, so mental shortcuts like doubling don't work here the way they do for length or weight.

Fever readings sometimes need converting too: a metric thermometer reading of 38.5 °C, described to a US-based telehealth service or a Fahrenheit-reading relative, becomes 101.3 °F — well above the commonly cited normal baseline of 98.6 °F (37 °C), which is itself an average that varies slightly by person and time of day.

Appliance and thermostat settings are the case people run into without planning for it. A US hotel room or rental thermostat is marked in Fahrenheit, so a room that feels right at 22 °C has to be dialled in at about 72 °F, and a fridge held at 4 °C shows as 39.2 °F on a US-made display. Freezers meet the same offset from the other side: −18 °C works out to −0.4 °F, which is why US storage guidance is written around a round 0 °F rather than a round metric figure.