Is there a sight calculator anywhere to tell me how much to move sights side to side? I need to change POI 3" at 35'. Thanks

YOu can do the math, if you remember your trigonometry from high school. I can do the calc. for you, but I need to know the distance between the front and rear sights on the firearm in question.

3 (desired change in inches) x sight radius in inches ÷ 420 (distance to target in inches) = amount to move sight in inches.