Tile Calculator
Enter your room size and tile size to get the tile count and number of boxes to buy — with the waste allowance built in so the last row doesn't come up short.
Waste allowance
10% straight lay · 15% diagonal or herringbone
Area (+10% waste)
88.0
sq ft (measured: 80.0)
Tiles needed
88
Counts use the tile's nominal size — standard grout gaps roughly offset the difference between nominal and actual tile dimensions. For L-shaped floors, measure the total square footage with the square footage calculator first, then divide by your tile's area here.
How Tile Estimates Work
Divide the floor area by one tile's area, then add waste for cuts at walls, breakage, and pattern matching. Tile is sold by the box, not the piece, so the box count is what you actually order — coverage per box is printed on the label and varies by product, typically 8–12 sq ft.
Formula
Tiles = (area × (1 + waste)) ÷ tile sq ft, rounded up Tile sq ft = (width in × length in) ÷ 144 12×12 = 1.0 sq ft 6×24 plank = 1.0 sq ft 12×24 = 2.0 sq ft 3×6 subway = 0.125 sq ft Example: 10×8 ft floor, 12×24 tile, 10% waste: 80 × 1.10 = 88 sq ft ÷ 2.0 = 44 tiles
Frequently Asked Questions
How many 12×12 tiles do I need for 100 square feet?
110 — a 12×12 tile covers exactly 1 sq ft, so 100 sq ft needs 100 tiles plus the standard 10% waste allowance for cuts and breakage. If a box covers 10 sq ft, that's 11 boxes.
Do grout lines change how many tiles I need?
Not enough to matter for an estimate. Tile sizes are nominal — a '12-inch' tile is usually a hair under 12 inches — and the grout gap roughly fills the difference, so counting with the nominal size lands very close. Grout width does change how much grout you buy, just not the tile count.
How many square feet does a box of tile cover?
Most floor tile boxes cover 8–12 sq ft, but it varies by tile size and manufacturer — large-format tiles often come 3–5 per box and planks 6–10. The coverage is printed on the box label; always order by that figure rather than assuming a standard.
Why should I buy all my tile at once?
Dye lots. Tiles fired in different production runs can differ visibly in shade and even size calibration, and the lot number on the box is the only guarantee of a match. Order everything — including the spare box for future repairs — from the same lot in one purchase.