Fahrenheit to Celsius Converter

This table covers the Fahrenheit values most commonly searched and converted, from well below freezing to a rolling boil.

To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit value, then multiply by 5/9 (or divide by 1.8). For example, 98.6°F - 32 = 66.6, then 66.6 × 5/9 = 37.0°C.

For a fast mental estimate without a calculator, subtract 30 from the Fahrenheit value, then divide by 2. It is not exact, but it gets close for everyday temperatures. For a precise result, use the real formula above or the calculator at the top of this page.

To go the other way, from Celsius back to Fahrenheit, multiply by 1.8 first, then add 32. For example, 37.0°C × 1.8 = 66.6, then 66.6 + 32 = 98.6°F. For that direction, use the Celsius to Fahrenheit Converter.

For the full range of temperature scales in one tool, including Kelvin, use the Temperature Converter.

A number of specific Fahrenheit readings come up constantly in real searches, most of them tied to body temperature and fever thresholds:

• 98.6°F = 37.0°C, the traditional average for normal human body temperature
• 100.4°F = 38.0°C, a commonly used medical threshold for a fever in adults
• 103°F = 39.4°C, generally considered a high fever that warrants medical attention
• 32°F = 0°C, the freezing point of water
• 212°F = 100°C, the boiling point of water at sea level
• -40°F = -40°C, the one temperature where both scales read the same number

Fever thresholds vary slightly between medical sources and by measurement method (oral, rectal, ear, or forehead), so treat these as general reference points rather than a diagnosis. For scientific and international contexts, temperature is often expressed in Kelvin instead; see the Kelvin to Celsius Converter for that conversion.