If you want to convert from Celcius to Fahrenheit , type c to f and if you want Fahrenheit to Celcius, type f to c If your wondering what Kelvin is, it's another temperature measurement that's Celcius plus 273. They use it for temperatures off the charts. (mainly used for Earth and other planetary temperatures)
Thanks to my dad for helping me with the equations, @ThBestOfThBest12 for inspiration, and my math teacher for obvious reasons. When you are converting F to C, it is sometimes off by a little bit. By a little bit, I mean a decimal. C to F is perfectly fine.