How to Determine How Much Tile is Needed
- 1). Divide the room (or area) into "invisible" rectangles.
- 2). Measure the length and width of each rectangle.
- 3). Calculate the square feet of each rectangle by multiplying the length times the width.
- 4). Add the square feet of each rectangle together. This is the square feet needed for coverage.
- 5). Multiply the square feet needed for coverage by 10 percent; add this to the total. This is the total square feet of tile needed.
Source...