Use this to get an idea of where a new wheel would sit vs your current wheels.
Enter your current wheel width, offset and if currently using a spacer. You ONLY need the width of a wheel and the offset. Diameter is not relevant.
New wheel is going further to the suspension: the wheel will be more tucked. You may also run into rubbbing. Most commonly on the shock tower.
New wheel is going further out to the fender: the wheel will be more poked. Issues here are fender rubbing the tire or just looking dumb, like a monster truck.
25.4 MM equals 1 inch.