A handy formula to convert notes to hertz

Image via Wikipedia

I don’t know why I didn’t find this among the top 3 google results, so I gave it some thought and the answer is pretty easy:

1. Convert your note to a number that represents the distance in half tones from middle A. Middle A should be 0, next A# should be 1 and Ab -1 and so on.
2. Frequency (in Hertz) = 440 x 2^(a/12), where a is the number from step 1.