Originally Posted by
cooker
I think "float" refers to how much you can tilt your foot from side to side without moving your heel, but perhaps it also refers to how much you can rotate without clicking out. "Release angle" is how far you rotate your heel out from the chain stay in order to click out of the pedal.
Float refers to the number of degrees of lateral movement you have at your heel whilst pivoting on the cleat. If your cleat set-up preserves symmetrical float, your release angle would be float/2. Some riders, e.g. those that ride toe out or toe in, angle their cleats to get a fit more suitable to them.