TOOLCelsius to Fahrenheit: How to Convert Temperature
To convert Celsius to Fahrenheit, multiply the temperature by 9/5 (which is 1.8) and add 32. So 20°C × 1.8 + 32 = 68°F. To go the other way — Fahrenheit to Celsius — subtract 32 first, then multiply by 5/9. Below you'll find a quick mental shortcut, a conversion table, and the reference points worth memorizing.
Key takeaways
- °C → °F: multiply by 1.8, then add 32.
- °F → °C: subtract 32, then multiply by 5/9.
- Quick estimate: double the °C and add 30 (close enough for weather).
- Convert any value exactly with the temperature converter.
The formulas
°C = (°F − 32) × 5/9
Both scales measure the same thing — how hot or cold something is — but they were built around different reference points, which is why the conversion needs both a multiply and an add. Celsius sets 0° at the freezing point of water and 100° at its boiling point. Fahrenheit puts those same two points at 32° and 212°, a 180-degree gap, which is where the 9/5 ratio (180 ÷ 100) comes from.
Quick mental shortcut
When you just need a ballpark — reading a foreign weather forecast, say — use this: double the Celsius number and add 30.
- 20°C → 20 × 2 = 40 → + 30 = 70°F (exact: 68°F)
- 30°C → 30 × 2 = 60 → + 30 = 90°F (exact: 86°F)
It runs a few degrees high at the top of the range, but for "is it t-shirt weather?" it's perfect. For anything precise — cooking, science, health — use the real formula or a converter.
Celsius to Fahrenheit table
| Celsius | Fahrenheit | What it feels like |
|---|---|---|
| 0°C | 32°F | Freezing (water freezes) |
| 10°C | 50°F | Cool / light jacket |
| 20°C | 68°F | Room temperature |
| 25°C | 77°F | Warm |
| 30°C | 86°F | Hot summer day |
| 37°C | 98.6°F | Body temperature |
| 100°C | 212°F | Boiling (water boils) |
Reference points worth memorizing
You rarely need an exact conversion in daily life — you need a feel for a handful of anchor points. Learn these and you can place almost any temperature:
- 0°C = 32°F — freezing. Below this and roads get icy.
- 20°C = 68°F — comfortable room temperature.
- 37°C = 98.6°F — normal body temperature; useful for spotting a fever.
- 100°C = 212°F — boiling water at sea level.
Frequently asked questions
How do you convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 (1.8) and add 32. For example, 20°C × 1.8 + 32 = 68°F.
What is 37 degrees Celsius in Fahrenheit?
37°C is 98.6°F, which is normal human body temperature. Using the formula: 37 × 1.8 = 66.6, plus 32 = 98.6°F.
Is there a quick way to estimate Celsius to Fahrenheit?
Double the Celsius value and add 30 for a rough estimate. For 20°C: 20 × 2 = 40, plus 30 = 70°F (the exact answer is 68°F). It's close enough for weather.
Related: Temperature Converter · Length Converter · all Converters