About this tool
This converter uses the standard formula: °F = (°C × 9/5) + 32, and the reverse, °C = (°F − 32) × 5/9. Each box recalculates the other on every keystroke and rounds the answer to at most two decimal places, so 21.3 °C appears as 70.34 °F rather than a long string of digits.
How to use the converter
- To go from Celsius, type the value into the Celsius (°C) box. Negative numbers and decimals both work.
- Read the answer in the Fahrenheit (°F) box, which fills in as you type.
- To go the other way, type into Fahrenheit (°F) instead and read the Celsius (°C) box.
- For a value you need often, use the printable chart below and its Print chart button.
Worked example
A weather app abroad shows 21.3 °C. Type 21.3 into Celsius (°C) and the Fahrenheit box shows 70.34: 21.3 × 9/5 = 38.34, plus 32 = 70.34 °F. Going the other way, typing 98 into Fahrenheit (°F) gives 36.67 in the Celsius box, because (98 − 32) × 5/9 = 36.666…, rounded to two decimals.
Common use cases
- Checking a weather forecast reported in the unit you're not used to
- Converting an oven or cooking temperature between recipe conventions
- Converting a body temperature or scientific measurement between scales
Things to watch out for
Celsius and Fahrenheit have different zero points and step sizes, so the relationship isn't a simple multiplication — always use the full formula (×9/5, then +32) rather than a rough estimate, especially for temperatures far from the 0-100°C range where quick mental shortcuts break down. At exactly -40 degrees, both scales read the same number — a useful sanity check if you want to verify a conversion by hand.
Quick answers: common Celsius to Fahrenheit conversions
20 degrees Celsius to Fahrenheit is 68 °F. 22 °C is 71.6 °F, 26 °C is 78.8 °F, 37 °C is 98.6 °F (normal body temperature) and 38 °C is 100.4 °F, the usual fever threshold. For any other value, C to F is multiply by 9/5 and add 32. To convert the other way, see the Fahrenheit to Celsius converter.
How to convert Celsius to Fahrenheit by hand
Multiply the Celsius temperature by 9/5 (or 1.8) and add 32. For 25 °C: 25 x 1.8 = 45, plus 32 = 77 °F. A mental shortcut is to double the Celsius number and add 30, which gives 80 °F for 25 °C. It is a few degrees off at higher temperatures, but good enough to decide whether you need a jacket.
Weather and oven temperatures
| Celsius | Fahrenheit | What it feels like or means |
|---|---|---|
| -40 °C | -40 °F | The two scales meet here |
| 0 °C | 32 °F | Water freezes |
| 10 °C | 50 °F | Cool day, light jacket |
| 20 °C | 68 °F | Room temperature |
| 30 °C | 86 °F | Hot summer day |
| 37 °C | 98.6 °F | Normal body temperature |
| 100 °C | 212 °F | Water boils at sea level |
| 160 °C | 320 °F | Slow baking |
| 180 °C | 356 °F | Common moderate oven setting |
| 200 °C | 392 °F | Hot oven for roasting |
| 220 °C | 428 °F | Very hot oven |
Why two temperature scales exist
Most of the world uses Celsius, where water freezes at 0 and boils at 100. The United States mainly uses Fahrenheit, where those points are 32 and 212. A one-degree change in Celsius equals 1.8 degrees in Fahrenheit, which is why the conversion is not a simple addition. If you travel or cook from recipes written abroad, keep this chart handy.
Celsius to Fahrenheit chart (printable)
A one-glance chart for everyday temperatures from −40 °C to 100 °C, with the reference points worth remembering highlighted, followed by oven temperatures in both directions. Use the Print chart button for a clean, ad-free copy to stick on the fridge or keep in a lab notebook.
| Celsius | Fahrenheit | Note |
|---|---|---|
| −40 °C | −40 °F | °C and °F read the same |
| −35 °C | −31 °F | |
| −30 °C | −22 °F | |
| −25 °C | −13 °F | |
| −20 °C | −4 °F | |
| −15 °C | 5 °F | |
| −10 °C | 14 °F | |
| −5 °C | 23 °F | |
| 0 °C | 32 °F | Water freezes |
| 5 °C | 41 °F | |
| 10 °C | 50 °F | |
| 15 °C | 59 °F | |
| 20 °C | 68 °F | Room temperature (typical) |
| 25 °C | 77 °F | |
| 30 °C | 86 °F | |
| 35 °C | 95 °F | |
| 37 °C | 98.6 °F | Normal body temperature (typical) |
| 40 °C | 104 °F | |
| 45 °C | 113 °F | |
| 50 °C | 122 °F | |
| 55 °C | 131 °F | |
| 60 °C | 140 °F | |
| 65 °C | 149 °F | |
| 70 °C | 158 °F | |
| 75 °C | 167 °F | |
| 80 °C | 176 °F | |
| 85 °C | 185 °F | |
| 90 °C | 194 °F | |
| 95 °C | 203 °F | |
| 100 °C | 212 °F | Water boils (at sea level) |
Oven temperatures: °C to °F
| Celsius | Fahrenheit (exact) | Nearest US dial setting |
|---|---|---|
| 150 °C | 302 °F | 300 °F |
| 160 °C | 320 °F | 325 °F |
| 170 °C | 338 °F | 350 °F |
| 180 °C | 356 °F | 350 °F |
| 190 °C | 374 °F | 375 °F |
| 200 °C | 392 °F | 400 °F |
| 210 °C | 410 °F | 400 °F |
| 220 °C | 428 °F | 425 °F |
| 230 °C | 446 °F | 450 °F |
| 240 °C | 464 °F | 475 °F |
| 250 °C | 482 °F | 475 °F |
US oven settings: °F to °C
| Fahrenheit | Celsius |
|---|---|
| 250 °F | 121.1 °C |
| 275 °F | 135.0 °C |
| 300 °F | 148.9 °C |
| 325 °F | 162.8 °C |
| 350 °F | 176.7 °C |
| 375 °F | 190.6 °C |
| 400 °F | 204.4 °C |
| 425 °F | 218.3 °C |
| 450 °F | 232.2 °C |
| 475 °F | 246.1 °C |
| 500 °F | 260.0 °C |
Source: thealltools.com/tools/celsius-to-fahrenheit
Body temperature chart: °C to °F
Thermometers sold outside the US usually read in Celsius, and a half-degree step is the resolution most people care about. Values below use °F = °C × 9/5 + 32, rounded half-up to one decimal place. This chart only converts units; it is not a guide to what counts as a fever, which depends on the thermometer type and where the reading is taken.
| Celsius | Fahrenheit |
|---|---|
| 35.0 °C | 95.0 °F |
| 35.5 °C | 95.9 °F |
| 36.0 °C | 96.8 °F |
| 36.5 °C | 97.7 °F |
| 37.0 °C | 98.6 °F |
| 37.5 °C | 99.5 °F |
| 38.0 °C | 100.4 °F |
| 38.5 °C | 101.3 °F |
| 39.0 °C | 102.2 °F |
| 39.5 °C | 103.1 °F |
| 40.0 °C | 104.0 °F |
| 40.5 °C | 104.9 °F |
| 41.0 °C | 105.8 °F |
| 41.5 °C | 106.7 °F |
| 42.0 °C | 107.6 °F |
Fahrenheit to Celsius for everyday weather
If you are reading a US forecast, this chart covers the common range in 10 °F steps, using °C = (°F − 32) × 5/9, rounded half-up to one decimal.
| Fahrenheit | Celsius |
|---|---|
| 0 °F | −17.8 °C |
| 10 °F | −12.2 °C |
| 20 °F | −6.7 °C |
| 30 °F | −1.1 °C |
| 40 °F | 4.4 °C |
| 50 °F | 10.0 °C |
| 60 °F | 15.6 °C |
| 70 °F | 21.1 °C |
| 80 °F | 26.7 °C |
| 90 °F | 32.2 °C |
| 100 °F | 37.8 °C |
The double-and-add-30 shortcut, and how far off it is
A popular mental shortcut is to double the Celsius number and add 30. Compared with the exact formula, the error is 0.2 × °C − 2 degrees Fahrenheit. That means the shortcut is exact at 10 °C (both give 50 °F), 2 °F too low at 0 °C (30 instead of 32), 2 °F too high at 20 °C (70 instead of 68) and 4 °F too high at 30 °C (90 instead of 86). It is fine for deciding what to wear, and worth avoiding for cooking, medicine or lab work. The reverse shortcut, subtract 30 and halve, has the matching error in the other direction.
Where Kelvin fits in
Scientific work often uses the kelvin, the SI unit of temperature. NIST defines the relationship with Celsius exactly: K = °C + 273.15. A kelvin step is the same size as a Celsius degree, so a rise of 1 °C is also a rise of 1 K and of 1.8 °F. Absolute zero, 0 K, is −273.15 °C, which works out to −459.67 °F.
Frequently asked questions
Multiply the Celsius temperature by 9/5, then add 32. For example, 20°C × 9/5 = 36, plus 32 = 68°F.
Those are water's freezing and boiling points at sea level. Celsius was designed around 0 and 100 for those two reference points, while Fahrenheit's scale places the same two points at 32 and 212 — both scales describe the same physical temperatures, just with different zero points and step sizes.
Yes — at -40 degrees, both scales read the same number: -40°C equals -40°F. It's the one point where the two scales intersect.
180 °C is exactly 356 °F (180 × 9/5 + 32). US oven dials usually step in 25 °F increments, so a recipe written for 180 °C is normally baked at 350 °F.
37.5 °C is exactly 99.5 °F. Multiply 37.5 by 9/5 to get 67.5, then add 32. Half a degree Celsius is 0.9 °F, which is why 37 °C (98.6 °F) and 37.5 °C differ by nearly a full degree on a Fahrenheit thermometer.
70 °F is about 21.1 °C. Subtract 32 to get 38, then multiply by 5/9, which gives 21.11 recurring. Each Fahrenheit degree is 5/9 of a Celsius degree, so nudging a US thermostat up or down by 1 °F changes the temperature by about 0.56 °C.
Absolute zero is −459.67 °F. It is defined as 0 kelvin, which equals −273.15 °C, and converting that with °F = °C × 9/5 + 32 gives −459.67. No temperature can be lower, and it is the zero point of both the Kelvin and Rankine scales.