Convert Celsius to Fahrenheit
Conversion Formula
°F = °C × 1.8 + 32To convert Celsius to Fahrenheit, use the formula above. This is the standard conversion factor used worldwide.
Conversion Table
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| 0 | 32.00 |
| 10 | 50.00 |
| 20 | 68.00 |
| 100 | 212.00 |
Why convert Celsius to Fahrenheit
Weather forecasts and oven temperatures outside the US, and a growing share of international recipes, are given in Celsius, and translating that into the Fahrenheit most Americans actually cook by is the point of this page. A fever reading of 38 C means little to someone who thinks in Fahrenheit until it's converted to just over 100 F.
Where the number comes from
The formula is F = C x 9/5 + 32, an affine relationship, not a simple multiplication, because the scales don't share a zero point: 0 C, where water freezes, sits at 32 F, not 0 F. The scales cross at exactly -40, the one point where both read the same number, a useful sanity check on a hand conversion.
Quick reference
| 0 C | 32 F | water freezes |
| 100 C | 212 F | water boils at sea level |
| 37 C | 98.6 F | normal human body temperature |
| -40 C | -40 F | the one point where both scales agree |
| 20 C | 68 F | a common room temperature setting |
| 180 C | 356 F | a common baking oven temperature |
Common mistakes
- The most consequential error is applying this formula to a temperature change rather than a reading: a rise of 10 degrees Celsius is a rise of 18 degrees Fahrenheit, not the result of plugging 10 into the full formula, since the plus-32 offset applies only to a fixed point, not a gap between two points.
- People also drop the plus-32 term entirely, producing a number that's proportionally right but wrong by 32 degrees, enough to turn a comfortable room into a freezing one.
Frequently Asked Questions
Why do Celsius and Fahrenheit meet at -40?
It falls directly out of the formula: setting C equal to C x 9/5 + 32 and solving gives C = -40, the unique point where the affine offset and the scale factor cancel exactly.
How do I convert a temperature change, not a specific reading?
Multiply the change in Celsius by 9/5 (1.8) with no plus-32 term, since the offset only positions the scale's zero point and does not apply to a difference between two readings.
What's a fast mental shortcut for Celsius to Fahrenheit?
Double the Celsius figure and add 30. It isn't exact but stays within a couple of degrees for everyday temperatures, close enough for deciding what to wear.
Why does my oven show a rounder Fahrenheit number than the exact conversion gives?
Oven dials and recipes round to the nearest 5 or 25 degrees Fahrenheit for convenience, so a recipe's stated 350 F is itself a rounded figure, not a precise conversion from a specific Celsius setting.