There is a PF I am thinking of recruiting but I believe he would be a better SF or SG. Is there a formula or link that can help me with determining his potential at other positions?

Listed position is purely cosmetic and has no impact on the players potential so what you see listed is identical to how they would perform at a different position. When evaluating a recruit or a player on your current roster you should consider what position they would/will be best at based on their skill set and potential. I (and most coaches) very commonly play PGs at SF or Cs at PF or any number of combinations.

If you are using the "Player Roles" functionality and trying to figure out overall score at a different position, you have to recalculate yourself although I think most would tell your Player Roles overall score is more of just a guideline, its always better to look at the underlying skills.

Exactly what Texas said. This isn't GD where changing positions penalizes a player or adjusts their ratings. The position listed is purely cosmetic.

I've recruited SG's I've flexed to PF's, SF's I've converted into PG's, etc.

Changing positions pretty much only impacts two things to my awareness: awards and likelihood a player may take an RS since I believe the formula for acceptance accounts for how many other players you have at the position but I could be wrong on that one.