Celsius to Fahrenheit: Formula, Table & Common Temperatures

To convert Celsius to Fahrenheit, multiply by 9/5 (1.8) and add 32. For example, 20°C × 1.8 + 32 = 68°F. To go the other way, subtract 32 first, then multiply by 5/9.

The formulas

• °F = °C × 9/5 + 32
• °C = (°F − 32) × 5/9

Temperature is different from length or weight: the scales have different zero points, so you add 32 as well as scaling — you cannot just multiply.

Quick reference

• −40°C = −40°F (the scales meet here)
• 0°C = 32°F (water freezes)
• 10°C = 50°F
• 20°C = 68°F (room temperature)
• 30°C = 86°F
• 37°C = 98.6°F (body temperature)
• 100°C = 212°F (water boils)

A fast mental trick

Double the Celsius value and add 30 for a rough Fahrenheit estimate: 20°C → about 70°F. It is close enough for weather, though not exact.

Do it precisely

The unit converter handles °C ↔ °F ↔ Kelvin with exact live updates, in your browser. Related: How to convert cm to inches.