Tile measuring guide & FAQs
A simple three-wall shower example
For a back wall that is 5 feet wide and 7 feet high, plus two side walls that each measure 3 by 7 feet, the wall area is 35 + 42 = 77 square feet before openings. Add a 15% extra allowance for a planned purchase area of 88.55 square feet; at 15 square feet per box, that is six whole boxes.
Subtract niches carefully
The openings field is expressed in square feet (or square meters) per repeated wall. Subtract only parts that truly receive no tile. A recessed shower niche still needs tile on its return surfaces, so it may not reduce overall ordering; complex niches often increase cutting work.
Shower waterproofing is separate
A square-foot estimate does not confirm that your shower meets waterproofing, substrate, slope or building requirements. Check local regulations and manufacturer instructions and consider a professional where needed. TilePilot does not size waterproofing membranes or grout.
Frequently asked questions
How do I estimate three shower walls?
Enter the back wall and each side wall, or use Repeat × 2 if the sides are the same size. Measure only walls that will receive the selected tile.
Does this include shower floor or waterproofing?
No. Add the floor as another zone only if you plan to use the same tile product and box coverage. Shower floor tile, membrane, pan, curb and waterproofing require separate planning.
How accurate is this tile calculator?
The measured area and box rounding follow explicit formulas. Tile cuts, uneven walls, product sizes, coverage labels and installation methods can change the actual amount needed, so use the result as a purchase-planning estimate.
Method & sources: The formulas are documented in our methodology. Reference guidance: Home Depot — how to lay tile and backsplash measurements. Retail guidance is informational, not a partnership or endorsement. Updated Nov 3, 2026.