Guide
How much tile do I need?
Four steps: measure the surface, subtract openings, add a waste allowance for your layout pattern, and round up to full boxes. Here is each step the way an estimator does it — and the same math the TileCount app runs per space.
1. Measure the surface
Floors: width × length in feet. Walls, backsplashes, showers, and tub surrounds: width × height per wall, added together. Measure in feet and inches, then convert inches to decimals (6 inches = 0.5 ft).
2. Subtract openings
Doors, windows, and fixtures you will not tile behind come out of the total: subtract width × height for each. A tiled niche adds a little back — the back of the niche replaces the wall cutout, so only the short return sides add area.
3. Add pattern waste
Cutting waste depends on the layout. Typical planning allowances — the same defaults TileCount uses:
- Stacked — 8%
- Straight — 10%
- Running bond — 10%
- Diagonal — 15%
- Herringbone — 20%
- Chevron — 25%
Small rooms with many edges, out-of-square walls, and natural stone (dye-lot and breakage risk) can justify more.
4. Round up to full boxes
Tile sells by the box. Divide the waste-adjusted area by the coverage printed on the box and round up:
boxes = (net area × (1 + waste%)) ÷ sq ft per box, rounded up
Worked example
A 10 × 12 ft floor in a straight layout with 10 sq ft per box:
- Net area: 10 × 12 = 120 sq ft
- With 10% waste: 120 × 1.10 = 132 sq ft
- Boxes: 132 ÷ 10 = 13.2 → round up to 14 boxes (140 sq ft purchased)
Or skip the arithmetic: the free tile calculator runs this exact formula.
Beyond the tile itself
A real material list also needs thinset (coverage varies by trowel size and tile format), grout (joint width, tile size, and joint depth drive it — small tile uses far more grout per square foot), backer board or uncoupling membrane, waterproofing for wet areas, movement-joint sealant, and trim. The TileCount app estimates all of these per space and rolls them into a client-ready proposal; the one-surface Quick Calc is free.
Estimates are not guarantees. Always verify quantities, dimensions, box coverage, manufacturer instructions, local code requirements, and jobsite conditions before ordering materials, signing a contract, or starting work.