How Many Tiles Do I Need? Simple Guide for Any Room
How many tiles do I need? The math is easy: area + 10% waste + box rounding. Charts for common rooms and buying tips included.
How to count tiles for any room
Tile math has three steps: area, tile size, and waste. Get these right and you will never run out mid-project — or buy boxes you cannot return.
1. Find the floor area
Length × width. A 12×12 room is 144 sq ft. A 15×12 kitchen is 180 sq ft.
2. Convert to tiles
A 12×12 inch tile covers exactly 1 sq ft, so 144 sq ft = 144 tiles. For other sizes: tile area in sq ft = (width × length in inches) ÷ 144.
3. Add waste (the part everyone forgets)
Waste covers cuts at walls, breakage and future repairs:
| Layout | Waste allowance |
|---|---|
| Straight lay, square room | 5-10% |
| Standard rooms with cuts | 10% |
| Diagonal / herringbone | 15% |
| Large format tiles (24×24) | 15%+ |
4. Round up to boxes
Divide by the tiles-per-box on the label and round up. Example: 144 × 1.10 = 158.4 → 159 tiles → if 10 per box → 16 boxes.
Tiles needed quick chart (10% waste)
| Room | Area | 12×12 tiles | Boxes (10/box) |
|---|---|---|---|
| 10×10 | 100 sq ft | 110 | 11 |
| 12×12 | 144 sq ft | 159 | 16 |
| 15×12 | 180 sq ft | 198 | 20 |
| 20×15 | 300 sq ft | 330 | 33 |
Buying tips
- Buy one extra box and keep it — dye lots vary, and matching later is often impossible
- Check the box label: "coverage 10 sq ft" means 10 tiles per box for 12×12
- For walls, use the same math with wall height × width as your area
FAQ
How many 12x12 tiles in a 10x10 room?
100 sq ft × 1.1 waste = 110 tiles → 11 boxes (10 per box).
How much grout for 144 sq ft of 12x12 tile?
With 1/4-inch joints and 3/8-inch thick tile, about 9-11 lb — one 25 lb bag covers it with room to spare.
Do I need extra tiles for future repairs?
Yes — keep at least 3-5 tiles in a labeled box. Floors get chips and you will want an exact match.
Need a different size?
Our free calculators give you the exact answer in seconds.