Celsius, Fahrenheit and Kelvin
Convert temperatures between the three scales in use. Temperature is the one conversion here that is not a multiplication: the scales start in different places, so 0 °C is 32 °F rather than 0 °F, and the answer comes from a formula rather than a ratio. The formula is printed under every result so you can check it. Nothing is uploaded or saved.
- Nothing is uploaded or saved
- Works offline
Temperature converter
Celsius to Fahrenheit
77°F
25 °C = 77 °F
°F = °C × 9/5 + 32
°C = (°F − 32) × 5/9
The same amount in every unit
Common temperature conversions
Every figure below is produced by the same conversion code as the calculator above, so the two can never disagree.
Celsius to Fahrenheit and Kelvin
| Celsius (°C) | Fahrenheit (°F) | Kelvin (K) |
|---|---|---|
| -40 | -40 | 233.15 |
| -30 | -22 | 243.15 |
| -20 | -4 | 253.15 |
| -10 | 14 | 263.15 |
| 0 | 32 | 273.15 |
| 5 | 41 | 278.15 |
| 10 | 50 | 283.15 |
| 15 | 59 | 288.15 |
| 20 | 68 | 293.15 |
| 25 | 77 | 298.15 |
| 30 | 86 | 303.15 |
| 35 | 95 | 308.15 |
| 37 | 98.6 | 310.15 |
| 40 | 104 | 313.15 |
| 50 | 122 | 323.15 |
| 60 | 140 | 333.15 |
| 80 | 176 | 353.15 |
| 100 | 212 | 373.15 |
Kelvin starts at absolute zero, so it has no negative values and no degree sign — write 300 K, not 300 °K.
Fahrenheit to Celsius
| Fahrenheit (°F) | Celsius (°C) | Kelvin (K) |
|---|---|---|
| -40 | -40 | 233.15 |
| 0 | -17.7777777778 | 255.372222222 |
| 10 | -12.2222222222 | 260.927777778 |
| 20 | -6.66666666667 | 266.483333333 |
| 32 | 0 | 273.15 |
| 40 | 4.44444444444 | 277.594444444 |
| 50 | 10 | 283.15 |
| 60 | 15.5555555556 | 288.705555556 |
| 70 | 21.1111111111 | 294.261111111 |
| 80 | 26.6666666667 | 299.816666667 |
| 90 | 32.2222222222 | 305.372222222 |
| 98.6 | 37 | 310.15 |
| 100 | 37.7777777778 | 310.927777778 |
| 110 | 43.3333333333 | 316.483333333 |
| 150 | 65.5555555556 | 338.705555556 |
| 200 | 93.3333333333 | 366.483333333 |
| 212 | 100 | 373.15 |
Kelvin starts at absolute zero, so it has no negative values and no degree sign — write 300 K, not 300 °K.
Oven temperatures, Celsius to Fahrenheit
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| 120 | 248 |
| 140 | 284 |
| 150 | 302 |
| 160 | 320 |
| 170 | 338 |
| 180 | 356 |
| 190 | 374 |
| 200 | 392 |
| 210 | 410 |
| 220 | 428 |
| 230 | 446 |
| 240 | 464 |
How it works
- 1
Type the temperature
Negative values are expected here rather than tolerated — type a minus sign in front and it is kept. −40 is a perfectly ordinary entry on this page.
- 2
Pick the two scales
Celsius, Fahrenheit and Kelvin. The panel beside the result shows the temperature on all three at once, which is usually faster than converting twice.
- 3
Read the formula under the result
What appears under the answer is the actual formula, not a ratio, because there is no “one degree Celsius in Fahrenheit” figure to quote. A difference of 1 °C is 1.8 °F, but a temperature of 1 °C is 33.8 °F — the same number means two different things depending on whether you are measuring a gap or a point, and printing a single ratio would silently pick the wrong one.
- 4
Check it against the tables
Celsius to Fahrenheit from freezing to boiling, and Fahrenheit back to Celsius across ordinary weather and oven ranges. Both are generated by the same code that answers the field above.
Frequently asked questions
What is the formula for Celsius to Fahrenheit?
°F = °C × 9/5 + 32, and in the other direction °C = (°F − 32) × 5/9. The multiply-then-add is what separates temperature from every other conversion on this site. Metres, litres and kilograms all share a zero, so a single ratio does the whole job. Celsius and Fahrenheit do not — their zeros are 32 degrees apart — so multiplying by 1.8 and stopping is not merely imprecise, it is wrong at every single temperature. Try to solve 1.8c = 1.8c + 32 and there is no answer.
Is there a temperature where Celsius and Fahrenheit read the same?
Exactly one: −40. Minus forty Celsius is minus forty Fahrenheit, which you can check by solving c = c × 9/5 + 32 and getting c = −40. It is the only crossing point the two scales have, and it is why cold-weather ratings sometimes just say “−40” and leave the unit off entirely.
What is absolute zero?
0 Kelvin — which is −273.15 °C, or −459.67 °F. It is not simply “very cold”: it is the point at which a system has given up all the thermal energy it can, so there is nothing below it to reach. That is why the Kelvin scale starts there, why it has no negative numbers, and why it is written without a degree sign: you write 300 K, not 300 °K.
Why does Kelvin look like Celsius plus 273?
Because that is exactly what it is. The two scales use an identical step size — one kelvin is one degree Celsius — and differ only in where they start, so the conversion is a pure offset: K = °C + 273.15. Fahrenheit is the awkward one, because its degrees are 5/9 the size as well as starting somewhere else, so converting to it involves both a stretch and a shift.
What is 37 °C in Fahrenheit?
98.6 °F exactly. The apparent precision of that figure is an artefact of the conversion rather than of the measurement: it came from a rounded 37 °C, and normal body temperature varies through the day and from person to person. Treat 98.6 as “37 converted”, not as a number known to a tenth of a degree.
Why do oven charts say 200 °C is 400 °F when this page says 392?
Because oven charts round to the nearest 25 °F, and this page does the arithmetic. The exact conversion of 200 °C is 392 °F; cookbooks print 400 because that is a mark on the dial, and no domestic oven holds a temperature to eight degrees anyway. Use the exact figure to understand the conversion and your dial’s nearest setting to cook.
Is anything I type uploaded or saved?
No. The conversion happens in your own browser, there is no server behind this site, and nothing is written to your device.