Shower Tile Calculator
A shower is really two tile jobs: large-format tile on the walls and small tile on the sloped floor. This sizes both, plus the backer board and waterproofing behind them.
How this calculator works
- Wall area = tiled wall length × height. For 3 walls that is width + 2 × depth.
- Floor mosaic covers width × depth; waterproofing adds a 6-inch upturn around the floor perimeter.
- Cement board comes in 3×5 ft (15 sq ft) sheets, sized here with 10% extra for cuts.
Shower tile questions
How high should shower tile go?
The IRC (R307.2) requires a nonabsorbent surface to at least 6 feet above the floor in showers. Many people tile to the ceiling, or to 7 or 8 feet, for a cleaner line.
Why small tile on the shower floor?
The floor slopes to the drain (typically 1/4 inch per foot). Small tiles such as 2×2 follow the slope and give more grout lines for grip.
Is cement board waterproof?
No. Cement board is water-resistant but not waterproof. A liquid membrane or sheet membrane over it, or a traditional pan liner system, is what keeps water out of the wall.