How the conversion works
Temperature scales differ in two ways at once: where they place zero and how big each degree is. That is why converting is not a single multiplication like it is for length or weight.
To keep things consistent the tool routes everything through Celsius. It first turns your input into Celsius, then converts that to the unit you asked for.
- Fahrenheit: degrees Celsius times 1.8, then add 32.
- Kelvin: degrees Celsius plus 273.15.
Reading the result
The answer is shown in the unit you selected. A few anchor points help sanity-check it: water freezes at 0 C, 32 F and 273.15 K, and boils at 100 C, 212 F and 373.15 K.
Practical tips
Kelvin has no negative values in normal use because it starts at absolute zero, the coldest possible temperature. A negative Kelvin result usually means the input was wrong.
- For a quick mental estimate, double Celsius and add 30 to approximate Fahrenheit.
- Body temperature near 37 C is about 98.6 F.
Common mistakes
A frequent error is forgetting the offset and only scaling by 1.8, which is wrong for any non-zero temperature. The constant 32 (or 273.15 for Kelvin) must be included.
Check that the from and to units are not the same, or the value will simply pass through unchanged.
Formula
°F = °C·1.8 + 32; K = °C + 273.15