Subway Tile Spacing 1 8 . What size are subway tiles? 1/2 quarter round molding could also fill in the gap and will save you cutting tile, but might not be the aesthetic fit you're looking for. My Best Subway Tile Backsplash Installation Tips A Nod to Navy from www.anodtonavy.com We also plan to offset the subway tile by. There are even grout stains so you can change the color if you change your mind. Aug 17, 2020 at 17:03.