I'm sure that there are formulas but why would you want them? Unless you are attempting to design a foil, but then you would already know the formula.
What did you fly in the Navy?
2.0m Samurai 2
3.0m Samurai 2
4.9m Blade IV
5.5m Bullet
7.5m Frenzy 07
7.7m Crossfire
12.0m Frenzy 07
Flexi buggy for now.....