Celsius to Fahrenheit — Formula & Reference
The Celsius scale (°C) is used worldwide in science and by most countries. The Fahrenheit scale (°F) is primarily used in the United States.
Formula
Key Reference Temperatures
| Celsius (°C) | Fahrenheit (°F) | Reference |
|---|---|---|
| −40 | −40 | Both scales equal at this point |
| 0 | 32 | Freezing point of water |
| 20 | 68 | Room temperature |
| 37 | 98.6 | Normal body temperature |
| 100 | 212 | Boiling point of water |
Inverse formula (°F to °C)
Related Temperature & Unit Converters
Celsius to Fahrenheit: The Formula Explained
The conversion formula is F = (C × 9/5) + 32, or equivalently F = (C × 1.8) + 32. The 9/5 factor accounts for the different scale sizes: a degree Celsius is 1.8× larger than a degree Fahrenheit. The +32 offset shifts the zero point — water freezes at 0°C but 32°F. To reverse: C = (F − 32) × 5/9. A useful mental shortcut: double the Celsius value and add 30 for a rough estimate (works well between −10°C and 30°C, error ≤ 3°F).
Body temperature (37°C = 98.6°F), oven baking temperatures (180°C = 356°F), and fever thresholds (38°C = 100.4°F) are common real-world values. The US uses Fahrenheit for weather and cooking; most of the world uses Celsius. Weather forecasts in the US report 90°F summer highs (32.2°C), while European forecasts show 38°C heatwaves (100.4°F).
Celsius to Fahrenheit Key Values
| Celsius (°C) | Fahrenheit (°F) | Context |
|---|---|---|
| -40 | −40 | C and F scales meet |
| -20 | −4 | Cold winter |
| 0 | 32 | Water freezes |
| 20 | 68 | Room temperature |
| 37 | 98.6 | Body temperature |
| 100 | 212 | Water boils (sea level) |
