Celsius to Fahrenheit: Formula & Quick Conversions
·3 min read
To convert Celsius to Fahrenheit, use °F = (°C × 9/5) + 32. So 20°C = (20 × 1.8) + 32 = 68°F. To go back, °C = (°F − 32) × 5/9. Here's the formula, a quick mental shortcut, common reference points, and a free temperature converter.
The conversion formulas
- C → F: °F = (°C × 9/5) + 32
- F → C: °C = (°F − 32) × 5/9
The Temperature Converter flips between Celsius, Fahrenheit, and Kelvin instantly.
Fast mental math
For a rough Celsius-to-Fahrenheit estimate: double the Celsius and add 30. 20°C → 40 + 30 = 70°F (actual 68°F — close enough for weather). It drifts at extremes but is handy day to day.
Reference points worth memorizing
- 0°C = 32°F — water freezes
- 37°C = 98.6°F — body temperature
- 100°C = 212°F — water boils
- −40°C = −40°F — the one point where the scales meet
Bottom line
°F = (°C × 9/5) + 32, or double-and-add-30 for a quick estimate. For exact conversions across weight, length, and more, see everyday unit conversions or use the Temperature Converter.