Tile Calculator
Square feet, tile count, and thinset for floors and walls.
10% for straight layouts, 15% for diagonal or herringbone.
You need
88 sq ft
Round up to whole boxes using the coverage printed on the box.
- Tile count
- 88 tiles
- Thinset (50 lb bags)
- 2 bags
- Floor area
- 80 sq ft
Estimates only. Verify quantities before ordering.
How this is calculated
Area to buy = length x width x (1 + waste %). Tile count = area in sq in / tile area in sq in, rounded up. Thinset assumes one 50 lb bag per 75 sq ft with a 1/4 inch notch trowel; larger tile and uneven floors use more.
Enter the area and pick a tile size, and this calculator returns the square footage to buy, the piece count, and the thinset to set it. Tile is sold by the box with coverage printed on the label, so the primary number to carry to the store is square feet including waste; the piece count is a sanity check.
Waste matters more with tile than with most flooring because every cut piece at a wall is unusable on the opposite side. Use 10% for a straight lay in a simple room. Go to 15% for diagonal layouts, herringbone, large-format tile in small rooms, or any room with lots of jogs and pipes to cut around.
Tile for common room sizes
Rows assume 12 x 12 in tile with 10% waste and thinset at one 50 lb bag per 75 sq ft.
| Room size | Sq ft to buy | Tiles | Thinset |
|---|---|---|---|
| 5 x 8 ft (bathroom) | 44 sq ft | 44 tiles | 1 bags |
| 8 x 10 ft | 88 sq ft | 88 tiles | 2 bags |
| 10 x 10 ft | 110 sq ft | 110 tiles | 2 bags |
| 12 x 10 ft (kitchen) | 132 sq ft | 132 tiles | 2 bags |
| 15 x 12 ft | 198 sq ft | 198 tiles | 3 bags |
Common questions
How much extra tile should I buy?
10% beyond the measured area for straight layouts, 15% for diagonals and patterns. Also keep a few spare tiles after the job: dye lots vary between production runs, and a matching repair tile years later is worth far more than what the spares cost.
How much thinset do I need?
With a 1/4 inch square-notch trowel, a 50 lb bag sets roughly 75 to 85 square feet of small and mid-size tile. Large-format tile needs a deeper 1/2 inch notch and back-buttering, which can cut a bag's coverage to 40 or 50 square feet, so buy accordingly.
Do I need to worry about tile lippage with large tile?
Tiles 12 x 24 and larger are slightly bowed from firing, so offsets over 33% create visible lips between pieces. Use a maximum 1/3 offset for large-format tile, a medium-bed mortar, and a leveling-clip system if the substrate is not dead flat.
Does the subfloor matter for tile?
More than the tile does. Tile needs a stiff, flat base: cement board or an uncoupling membrane over wood subfloors, with deflection within L/360. Tile installed straight over a bouncy or flexing floor cracks at the grout lines no matter how good the tile is.