Feats

[Draxyx01]

So i have a question about the feat power strike. It states that for every 4 BAB, you take a -1 to melee attack rolls and a +2 to damage rolls. What if my BAB is 7.

[Orfamay Quest]

Always round down. That's a general rule of Pathfinder.

[Claxon]

For every 4 BAB...
So things happen at BAB 4, 8, 12, 16, 20.
The penalty doesn't increase and neither does the damage until you reach those points.

[kinevon]

Assuming you mean Power Attack, you have the following attack penalty/damage progression:

BAB 1-3 To hit -1, Damage +2
BAB 4-7 To hit -2, Damage +4
BAB 8-11 To hit -3, Damage +6
BAB 12-15 To hit -4, Damage +8
BAB 16-19 To hit -5, Damage +10
BAB 20 To hit -6, Damage +12