How do I work out how wide I can bluff?

I know that if I bet 75% pot on each street with a perfectly polarized range 34% of my flop bets need to be for value, since I'll bet the turn 70%, the river 70% and 70% of my river bets will be for value. (0.7)(0.7)(0.7)=0.34

When ranges aren't perfectly polarized and my bluffs have good equity how do i work out how often to bluff the flop? If my value bets are strong and bluffs have good equity can I bluff the flop a lot more than I can with a perfectly polarized range?