Temperature converter
Temperature is the one conversion you cannot do with a single multiplier, because the scales start at different zero points. Type a value and pick the scales; the formula used is shown under the result.
20 °C = 68 °F
Formula: °F = °C × 9/5 + 32
20 °C in every temperature unit
- degree Fahrenheit
- kelvin
- degree Rankine
Popular temperature conversions
How it works
Drag the thermometer
Two things change between the scales: where zero sits (32 °F is 0 °C) and how big a degree is (a Celsius degree is 1.8 Fahrenheit degrees). That is why you multiply and add.
20 °C=68 °F
20 × 1.8 = 36, then + 32 = 68
The “double it and add 30” shortcut gives 70 °F here, off by 2°. It is close only near 10 °C.
Oven temperatures, °F to °C
American recipes give oven settings in Fahrenheit. Exact Celsius values, plus the fan-oven setting (about 20 °C lower is the usual guidance from oven makers).
| °F | °C (exact) | Fan oven °C |
|---|---|---|
| 250 | 121.1 | 100 |
| 275 | 135 | 115 |
| 300 | 148.9 | 130 |
| 325 | 162.8 | 145 |
| 350 | 176.7 | 155 |
| 375 | 190.6 | 170 |
| 400 | 204.4 | 185 |
| 425 | 218.3 | 200 |
| 450 | 232.2 | 210 |
| 475 | 246.1 | 225 |
| 500 | 260 | 240 |
Questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 (1.8) and add 32. For example 25 °C × 1.8 = 45, plus 32 gives 77 °F.
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. For example 350 °F − 32 = 318, × 5/9 gives 176.7 °C.
At what temperature are Celsius and Fahrenheit equal?
At −40. Minus forty degrees Celsius is exactly minus forty degrees Fahrenheit.
What is kelvin?
The SI base unit of temperature. A kelvin is the same size as a Celsius degree, but 0 K is absolute zero, so K = °C + 273.15.
Can a temperature be below 0 K?
No. Zero kelvin (−273.15 °C, −459.67 °F) is absolute zero; the converter warns you if you go below it.