Your femur length and your shin length should be the cosine of the ideal angle of your knee at the bottom of the stroke, which for 74% of the population (among Anglos, anyway) is 176.34 deg. Don't forget to take into account the lengths of each toe and your ankles' flexibility.



Or just keep raising the seat, one centimeter at a time (at most), until the backs of your knees feel like you're doing a hurdler stretch. Then drop it back down an increment or two.

Basically, pain in the front of your knees = seat too low; pain in back = too high.