One thing to bear in mind is that you are counting future bets in the pot which you are (a) assuming will be made and (b) you will win.

Depending on the nature of your outs (and the skill of your opponents) you won't always get the calls that you are banking on e.g. KQJx if a T comes on the river how many calls will you actually get? Thus if you hold the A it would be dangerous to include say 3 big bets in your turn calculations just because there are 3 players going to the river. With regard to (b) you need to discount your outs properly - you'll split with another A, and what
about a potential flush?