Unit converter — Temperature
Degrees Fahrenheit to degrees Celsius converter
Convert degrees Fahrenheit (°F) to degrees Celsius (°C). Affine conversion using the standard temperature scale formulas.
Results are mathematically exact for the displayed precision. How we calculate.
Convert degrees Fahrenheit to degrees Celsius— the formula
Temperature scales aren't related by a single multiplier — they have different zero points. Convert degrees Fahrenheit to degrees Celsius using the affine formula below.
°C = (°F − 32) × 5 ÷ 9
Celsius/Kelvin: SI definitions. Fahrenheit: F = C × 9/5 + 32; Kelvin: K = C + 273.15 (BIPM SI Brochure §2.3.1).
Frequently asked questions
Why isn't Fahrenheit to Celsius a simple multiplication?
Temperature scales have different zero points. Fahrenheit and Celsius both measure how hot something is, but they start counting from different places — so converting requires both a scale (multiply) and an offset (add or subtract).What is 0 °F in °C?
0 °F = -17.7778 °C.Where do these formulas come from?
They're the SI standard definitions published by the BIPM (Bureau International des Poids et Mesures) in the SI Brochure. Fahrenheit is defined relative to Celsius (F = C × 9/5 + 32) and Celsius is defined relative to absolute zero (K = C + 273.15).