How Many Tiles Do I Need?
For standard 12x12in tile with a 1/8in grout joint in a straight layout, each tile effectively covers about 1.02 sq ft of floor once its grout joint is included — so add 10% waste to your room's area and divide by 1.02. For a different tile size, grout width, diagonal layout, or box count, the tile calculator handles those directly. This page is a quick reference table by room size, plus a worked example for a floor with a separate border or accent strip.
Tiles and boxes by room size
These figures assume 12x12in tile, a 1/8in grout joint, a straight (grid) layout at 10% waste, and boxes of 10 tiles — adjust proportionally if your box size differs.
| Room area | Tiles needed | Boxes (10/box) |
|---|---|---|
| 50 sq ft | 54 tiles | 6 boxes |
| 100 sq ft | 108 tiles | 11 boxes |
| 150 sq ft | 162 tiles | 17 boxes |
| 200 sq ft | 216 tiles | 22 boxes |
| 300 sq ft | 324 tiles | 33 boxes |
Waste factor guidance (10% straight, 15% diagonal/pattern): The Home Depot tile installation guide — a diagonal or patterned layout needs 15% waste instead of 10%, which raises every figure in this table by a few tiles; the calculator switches between the two directly.
A full example: field tile plus a border strip
A bathroom floor mixes two tile sizes: an 80 sq ft field area in 12x12in tile, bordered by a 20 linear ft, 4in-wide accent strip in a smaller 4x12in tile. These need two separate calculations, not one blended average — combining them would misestimate both, since the border's cut ratio is nothing like the field's. Field tile: 80 sq ft plus 10% waste = 88 sq ft, ÷ 1.02 sq ft per tile ≈ 87 tiles, or 9 boxes of 10. Border tile: the 20 ft × 4in strip is about 6.7 sq ft of area; each 4x12in accent tile with its grout joint covers roughly 0.35 sq ft, and a border needs the higher 15% pattern-cut waste since almost every piece meets a corner or a field-tile edge — 6.7 × 1.15 ≈ 7.7 sq ft, ÷ 0.35 ≈ 23 tiles, or 3 boxes if sold 8 to a box. The shopping list is two separate line items — 9 boxes of field tile and 3 boxes of border tile — not one combined order sized off an averaged area.