A basic equation that works for me (outside 45 yds)
30/40 rough - distance x 1.1
40/50 rough - distance time x 1.2
Depending upon club and distance to travel you will need to consider roll out. Wedges will have less roll out than mid or short irons. These shots will be affected by wind speed, wind direction, trajectory, green speed, elevation, and to a lesser extent spin on the ball.
Inside 45 yds to 18 yds punch (there is a punch distance table available in previous forum posts you just need to search for it). Again, roll out is a factor and you have to account for that.
Inside 17 yds I use the pitch shot ... this shot is dependent upon your ball, club, green speed, elevation, and is course dependent. You have to practice and make notes to hone in the distances