Welcome, and see how quick it is to get answers here. I will give rep to jfr for that.

BTW: To get it 1 in that usually means 1" = 5ft which is 1:60. So you will have to draw your map to a fixed scale so that say 200 pixels is 5ft then its a 200 pixel grid to apply. Lots of pre-made icons come in fixed scales so look out for stuff you want, see what scale they are in and design the map to be that scale. If your making all your own stuff up then ensure that whatever tokens you create are high enough res so that any map at highest res has token detail. Then you will have to scale tokens down on a per map basis depending on your desired map scaling.

If you were aiming to print that map for tabletop play then I would go with 300 pixels per 5ft real world and scale up/down all stuff to that.