I think you are talking about design formula. Which is fine, I didn't think about class specific gear until you just mentioned that.
((((Level * 0.10000) - 0.10000) + 1.000000) * VisualValue) * HealthValue
This formula is applied to every characters health. This includes damage as well. You calculate gear and stats and damage then simply apply a flat 10% per level. Its a method that simulates larger health pools without having larger health pools.
but a flat 10% seems kind of boring.