Tile Calculator — Tiles, Thinset & Grout
Tile, thinset, and grout in one shot. Enter your area and tile size for exact tile counts, boxes, and setting materials — with a realistic waste allowance. Free, instant, no signup.
Quick answer
Divide your area (in square inches) by the tile size, then add 15% for cuts and breakage (20%+ for diagonal layouts). An 80 sq ft floor with 12×12 tiles needs about 92 tiles.
How do you want to measure?
Tile size
15%
15% is the pro standard. Use 20%+ for diagonal layouts or natural stone.
Your tile estimate
Tiles to buy
92
80 sq ft incl. 15% waste
- Thinset (50-lb bags, rough)
- 2
- Grout (25-lb bags, rough)
- 1
Thinset and grout are rough estimates — check your product's coverage chart. Always buy from the same dye lot.
How the calculation works
- Area in square inches: sq ft × 144. Tile is sold by the piece, and pieces are measured in inches.
- Tiles: total square inches ÷ one tile's square inches, times 1 + waste%. Diagonal layouts and stone need more.
- Boxes: tiles ÷ tiles per box, rounded up. Check every box's shade number before you leave the store.
- Thinset: a 50-lb bag covers ~45 sq ft with a standard 1/4" trowel. Bigger tiles need bigger notches and more bags.
- Grout: roughly one 25-lb bag per 150 sq ft — a rough estimate, since joint width changes everything.
Waste guide by layout
| Layout | Waste to add | Why |
|---|---|---|
| Straight / grid | 10–15% | Minimal cuts, mostly edges |
| Running bond / subway | 15% | Offset cuts on every other row |
| Diagonal | 20% | Triangle offcuts at every border |
| Natural stone | 20%+ | Unusable veined or chipped pieces |
Tips from the pros
- Dry-lay first. Lay a row without mortar to check your cuts and centering before you commit.
- Back-butter large tiles (15"+) — spread thinset on the tile back too, for full coverage and no hollow spots.
- Buy all boxes at once and verify matching shade/caliber numbers on every box.
- Save a full box of tile plus leftover grout for future repairs — dye lots change.
- Seal natural stone before grouting, or grout haze will stain it permanently.
Common questions
Convert your area to square inches (sq ft × 144), divide by one tile's area in square inches, add 15% for waste and cuts, and round up. Example: 80 sq ft with 12×12 tiles = (80 × 144) ÷ 144 = 80 tiles × 1.15 = 92 tiles.