Convert Celsius to Fahrenheit (°C to °F)
To convert Celsius to Fahrenheit, multiply the Celsius temperature by 9/5 (1.8) and add 32. It is the conversion you need for US weather forecasts, oven temperatures in American recipes, body temperature and thermostat settings. This celsius to fahrenheit converter works both ways: type Celsius or Fahrenheit into either box above and the other box, the worked formula and the chart below update as you type.
The degree Celsius (°C) is named after the Swedish astronomer Anders Celsius, who proposed a 100-degree scale in 1742. Water freezes at 0 °C and boils at about 100 °C at sea level, and the scale is now formally defined from the kelvin. Celsius is the everyday scale for weather, cooking and medicine in nearly every country. A change of 1 °C equals a change of 1.8 °F, and 0 °C corresponds to 32 °F.
The degree Fahrenheit (°F) comes from the scale proposed by the physicist Daniel Gabriel Fahrenheit in 1724. Water freezes at 32 °F and boils at 212 °F, so 180 Fahrenheit degrees separate the two points. Each Fahrenheit degree is 5/9 of a Celsius degree, and 0 °F corresponds to −17.78 °C. Fahrenheit remains the everyday scale in the United States and a handful of other territories, for weather, ovens and body temperature.
How to convert celsius to fahrenheit with this tool
- Type a number into the Celsius (°C) box — it starts at 37 °C as an example.
- Read the answer in the Fahrenheit (°F) box and in the result panel, which also shows the formula with your number.
- To go the other way, type into the Fahrenheit box, or press the swap button to open the Fahrenheit to Celsius converter with your value carried over.
- Choose how many decimal places you want, or tap a quick value such as −40 °C, 0 °C, 20 °C.
- Press Copy result to paste the conversion into a message, spreadsheet or note.
Celsius to Fahrenheit converter features
Converts both ways
Type in the Celsius box to get Fahrenheit, or in the Fahrenheit box to get Celsius. The other box follows instantly.
Exact factor
Calculations use °F = °C × 9/5 + 32, and rounding is applied only to the answer you see — choose Auto or 0–10 decimal places.
Formula with your number
The working is shown under the result, for example (37 × 9/5) + 32 = 98.6 °F, so you can check it or copy the method.
Quick values and chart
Tap common values like −40 °C, 0 °C, 20 °C, or read the Celsius-to-Fahrenheit table further down this page.
Celsius to Fahrenheit formula
The formula is °F = (°C × 9/5) + 32. It is exact because the two scales are defined to line up: 0 °C is 32 °F, and every 100 Celsius degrees span exactly 180 Fahrenheit degrees.
The reverse formula is °C = (°F − 32) × 5/9 — or use the Fahrenheit to Celsius converter. Three worked examples:
- Normal body temperature (37 °C): (37 × 9/5) + 32 = 98.6 °F
- A moderate oven at 180 °C: (180 × 9/5) + 32 = 356 °F
- A cold winter day at −10 °C: (−10 × 9/5) + 32 = 14 °F
Converting temperature changes, not temperatures
The +32 in the formula only applies to actual temperatures. A temperature difference converts with the 9/5 factor alone: a rise of 10 °C is a rise of 18 °F, not 50 °F. If the forecast says tomorrow will be 5 °C warmer, that is 9 °F warmer.
The same goes for ovens and lab equipment — an oven that runs 10 °C hot is 18 °F off, whatever temperature it is set to.
Celsius to Fahrenheit quick reference
The values people look up most often, worked out with the exact factor:
- −40 °C = −40 °F
- 0 °C = 32 °F
- 20 °C = 68 °F
- 37 °C = 98.6 °F
Quick tip: Double it and add 30 for a fast weather estimate: 20 °C → 40 + 30 = 70 °F, close to the exact 68 °F. The shortcut drifts at high temperatures, so do not use it for ovens.
Related conversions: Celsius to Kelvin, Kelvin to Celsius and the full temperature converter.
Celsius to Fahrenheit conversion table
Values in Fahrenheit are rounded to 2 decimal places (more for very small numbers). For any value not listed, type it into the converter above.
| °C | °F | °C | °F |
|---|---|---|---|
| −40 | −40 | 40 | 104 |
| −30 | −22 | 45 | 113 |
| −20 | −4 | 50 | 122 |
| −10 | 14 | 60 | 140 |
| −5 | 23 | 70 | 158 |
| 0 | 32 | 80 | 176 |
| 5 | 41 | 90 | 194 |
| 10 | 50 | 100 | 212 |
| 15 | 59 | 120 | 248 |
| 20 | 68 | 150 | 302 |
| 21 | 69.8 | 160 | 320 |
| 22 | 71.6 | 180 | 356 |
| 25 | 77 | 200 | 392 |
| 30 | 86 | 220 | 428 |
| 35 | 95 | 250 | 482 |
| 37 | 98.6 |
Celsius to Fahrenheit FAQ
What is 20 °C in Fahrenheit?
20 degrees Celsius is 68 degrees Fahrenheit: (20 × 9/5) + 32 = 68 °F.
How do I convert celsius to fahrenheit?
Multiply the Celsius temperature by 9/5 (1.8) and add 32. For example, (40 × 9/5) + 32 = 104 °F. To convert back, subtract 32 from the Fahrenheit temperature and multiply by 5/9 — or use the Fahrenheit to Celsius converter.
What is 0 °F in Celsius?
0 degrees Fahrenheit is −17.78 degrees Celsius, because (0 − 32) × 5/9 = −17.78 °C.
What does 40 °C equal in Fahrenheit?
At what temperature are Celsius and Fahrenheit equal?
At −40. Solving °C × 9/5 + 32 = °C gives −40, so −40 °C = −40 °F. It is the only point where both scales show the same number.