I'm following the info on http://www.rfcandy.biz/communication/imp_lc.html to build an LC Meter. I have the basic design down and my pic16F690 is reading and displaying both frequencies. My problem is with the math. I need to calculate the formula, L = 1/(C*(2Pi)^2) * (1/f2^2 - 1/f1^2) Where the C value is in the pico farads, f is in Mhz and L is in uH. The pic16 doesn't seem to do so well with this calculation. So I need a variable with 18 decimal places?? 2^32 isn't enough. What can I do to get this calculation?