Fahrenheit to Celsius: Formula, Conversion Chart, and Worked Examples
To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9. This guide shows the formula with worked examples, a reference chart for common temperatures, and quick mental-math shortcuts.
To convert Fahrenheit to Celsius, subtract thirty-two from the Fahrenheit value, then multiply by five-ninths. The formula is
C = (F - 32) × 5/9. Three anchor points cover most everyday needs: water freezes, body temperature sits in the middle, and water boils.
Skip the arithmetic with our Fahrenheit to Celsius converter. Read on for the method, the chart, and a mental shortcut.
The formula, step by step
Subtract first, then multiply. Take thirty-two off the Fahrenheit value, then multiply what remains by five-ninths. The order matters, since flipping it gives the wrong answer.
A hot summer day. Run a warm reading through both steps and the answer lands on a round number.
A cool afternoon. A milder reading works the same way.
Normal body temperature. Decimals carry through to the final step before rounding.
A negative reading. Negatives stay negative the whole way through, and this value is the point where both scales read the same.
A mental shortcut for rough conversions
Subtract thirty, then halve. When you only need a ballpark figure and have no calculator, round the offset down and divide by two instead of multiplying by five-ninths. It is quick and close enough for weather.
The shortcut stays accurate to roughly two degrees Celsius across the everyday range. Use it for quick estimates and the real formula when precision matters.
Reference chart for common temperatures
These anchor values cover freezing, comfort, fever, and the kitchen. More cooking-specific values sit in our common temperature conversions guide.
Why the formula has a thirty-two and a five-ninths
The two scales start at different points. Fahrenheit and Celsius do not just use different units, they also set their zero in different places, so a conversion has to shift the origin and rescale the gap.
The thirty-two shifts the origin so both scales agree on freezing. The five-ninths is the Celsius range divided by the Fahrenheit range, which compresses the wider Fahrenheit span into the narrower Celsius one.
Going the other way: Celsius to Fahrenheit
Reverse the operations and the order. To convert back, multiply by nine-fifths first, then add thirty-two. Our Celsius to Fahrenheit guide walks through it in full, or use the Celsius to Fahrenheit calculator for any value.
The fastest route to an exact answer is the Fahrenheit to Celsius converter, which shows the worked steps for any value you enter.
Common questions
Subtract thirty-two from the Fahrenheit value, then multiply the result by five-ninths: C = (F - 32) × 5/9. Always subtract before you multiply.
Yes. Subtract thirty from the Fahrenheit value, then divide by two. It is accurate to about two degrees Celsius across normal weather temperatures, so use the exact formula when precision matters.
The two scales set their zero point differently, so subtracting thirty-two lines up the freezing point. Multiplying by five-ninths rescales Fahrenheit's wider degree span down to match Celsius.
They meet at one point, where both scales show the same negative value. Below and above it the two readings always differ.
Multiply the Celsius value by nine-fifths, then add thirty-two: F = C × 9/5 + 32. Multiply before you add.
