When you are remodeling your shower and you want to put in new shower tiles, you need to know how many square feet of tiles you'll need. Since most showers are rectangular in shape, you need to use the area formula for calculating square feet.
Measure the length of one of the walls that you are going to tile. By way of example, assume this measures 7 feet.
Measure the width of the same wall that you previously measured. By way of example, assume this side measures 4 feet.
Multiply the two sides together to calculate square feet. In the example, 7 times 4 equals 28 feet squared.
Repeat for any other walls or floor that you want to replace.