How to convert Celsius to Fahrenheit
To convert Celsius to Fahrenheit, multiply by 9/5 (1.8) and add 32. Unlike length or weight, temperature scales have a different zero point, so there is an offset of 32 degrees as well as a scaling factor of 1.8. That is why you cannot simply multiply — you also have to shift.
For example, 20°C × 1.8 + 32 = 68°F. Water freezes at 0°C (32°F) and boils at 100°C (212°F). A quick mental shortcut is to double the Celsius value and add 30 — 20°C → about 70°F — which is close enough for weather but not exact.
Where you’ll use Celsius to Fahrenheit
Most countries report temperature in Celsius, while the United States (and a few others) use Fahrenheit. Converting between them comes up constantly for travellers and anyone following international news, recipes or health advice:
- Weather: understanding a forecast abroad, or a US visitor reading a European weather app.
- Body temperature and fever: a thermometer reading in Celsius that you want to check against the familiar 98.6°F, or spotting a fever above 38°C (100.4°F).
- Cooking and ovens: recipes that give oven temperatures in Celsius when your oven dial is in Fahrenheit.
- Thermostats and appliances: setting heating, fridges or air conditioning bought in a different market.
- Science homework: converting lab or textbook values between the two scales.
The Celsius and Fahrenheit scales
The Celsius scale sets 0° at the freezing point of water and 100° at its boiling point (at sea level), dividing that range into 100 equal degrees. The Fahrenheit scale, devised by Daniel Fahrenheit in the early 1700s, puts water’s freezing point at 32° and boiling at 212° — 180 degrees apart. Because 180 ÷ 100 = 1.8, each Celsius degree equals 1.8 Fahrenheit degrees, which is where the factor in the formula comes from.
Celsius to Fahrenheit conversion table
| Celsius | Fahrenheit |
|---|
Everyday temperatures in both scales
| What it is | Celsius | Fahrenheit |
|---|---|---|
| Freezing water | 0 °C | 32 °F |
| Cold winter day | 5 °C | 41 °F |
| Room temperature | 20 °C | 68 °F |
| Warm summer day | 30 °C | 86 °F |
| Body temperature | 37 °C | 98.6 °F |
| Fever threshold | 38 °C | 100.4 °F |
| Boiling water | 100 °C | 212 °F |
Worked examples
Convert 20°C to Fahrenheit
20 × 1.8 + 32 = 68°F — a mild room temperature.
Convert 37°C to Fahrenheit (body temperature)
37 × 1.8 + 32 = 98.6°F, the classic “normal” reading.
Convert 180°C (a common oven setting) to Fahrenheit
180 × 1.8 + 32 = 356°F, usually rounded to 350°F on a US oven dial.
Frequently asked questions
0°C equals 32°F, the freezing point of water.
About 37°C, which is 98.6°F. A reading of 38°C (100.4°F) or higher is generally considered a fever.
At −40 degrees: −40°C equals −40°F.
350°F is about 177°C, which most recipes round to 180°C. Common bake temperatures: 325°F ≈ 160°C, 375°F ≈ 190°C, 425°F ≈ 220°C.