Celsius to Fahrenheit (°C to °F)

How to convert Celsius to Fahrenheit

Multiply by 9/5 (which is 1.8), then add 32:

°F = °C × 9/5 + 32

30 °C × 1.8 = 54, and 54 + 32 = 86 °F. Order matters: multiply first, then add. For temperatures below zero, keep the sign — −10 °C × 1.8 = −18, and −18 + 32 = 14 °F. The converter shows these steps with your number on the “worked out” line. To go the other way, subtract 32 and multiply by 5/9, or type the Fahrenheit into the second field.

Converting in your head

Double the Celsius and add 30. The result line labeled quick estimate shows it next to the exact answer:

The rule is exact at 10 °C and good enough for weather between about −5 and 25 °C. It drifts for hot days and fails for ovens: 200 °C would come out as 430 °F instead of 392 °F, so the converter shows the estimate only between −20 and 40 °C.

Weather temperatures

Oven temperatures

Recipes from Europe, Australia and Canada give oven temperatures in Celsius, and U.S. ovens are marked in steps of 25 °F. Use the nearest setting:

A fan (convection) oven in a European recipe runs about 20 °C lower than a conventional one; if the recipe gives both, convert the conventional figure.

Reference points

Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea level, so 100 Celsius degrees span 180 Fahrenheit degrees — the 9/5 in the formula. Normal body temperature is about 37 °C (98.6 °F); a thermometer reading of 38 °C is 100.4 °F. The scales meet at −40. For the reverse, use Fahrenheit to Celsius; for science, Celsius to kelvin. Other measures from the same recipes convert with mL to ounces and grams to ounces; for distances in a foreign weather report, km to miles.