Tile Calculator

Measure the floor or wall you want to tile and enter its length and width in feet — for a 10 ft by 12 ft room that's `10` and `12`. Then enter your tile size in inches (a standard tile is `12` by `12`). That's it: the calculator instantly shows how many tiles you need, with a sensible 10% waste allowance already built in. Need more control? Open More options to switch to metric, change the waste percentage, add a grout gap, set the tiles-per-box for your product, or enter a price per box to estimate total cost.

The core idea is simple: divide the area you are covering by the area of one tile. A 10 ft x 12 ft floor is 120 square feet, and a 12 in x 12 in tile covers exactly 1 square foot, so you need about 120 tiles — before waste. But you never buy the bare minimum. Cuts around edges, doorways and corners, plus the occasional cracked tile, mean 10% extra is the standard rule of thumb (15–20% for diagonal or herringbone layouts that produce more cut pieces). That is why this tile calculator adds a waste allowance automatically and then rounds up to whole tiles and whole boxes — because you can only buy complete units at the store.

Tiles needed = ⌈ (Area ÷ Tile area) × (1 + Waste%) ⌉

- Area = floor length × floor width (converted to the same units)
- Tile area = (tile length + gap) × (tile width + gap)
- Boxes = ⌈ Tiles needed ÷ Tiles per box ⌉
- Cost = Boxes × Price per box

The `⌈ ⌉` brackets mean *round up* — you always round tiles and boxes up to the next whole unit. Adding the grout gap to each tile's dimensions accounts for the space the spacers take, so you don't over-order on wide joints.

Example 1 — Standard bathroom floor. A 5 ft x 8 ft floor is 40 sq ft. With 12 in x 12 in tiles (1 sq ft each) and 10% waste: 40 × 1.10 = 44 tiles. At 10 tiles per box you buy 5 boxes.

Example 2 — How many 12x24 tiles for a 10x12 room? 120 sq ft ÷ 2 sq ft per tile = 60 tiles, × 1.10 = 66 tiles. At 8 per box that's 9 boxes.

Example 3 — Subway wall with grout. A 40 sq ft backsplash in 3 in x 6 in tiles with a 1/8 in gap: each tile plus gap covers about 0.132 sq ft, so ~303 tiles × 1.15 (lots of cuts) ≈ 349 tiles.

- Buy from one batch. Tile color shifts slightly between production runs ("dye lots"). Ordering all your boxes at once — including the waste overage — keeps the color consistent.
- Keep the leftovers. Store a few spare tiles after the job. If one cracks in year three, an exact-match replacement is priceless.
- Go higher on waste for busy layouts. Straight lay wastes ~10%; diagonal, herringbone and small mosaic sheets can waste 15–20%.
- Round rooms and L-shapes: split them into rectangles, calculate each, then add the tile counts together.
- Don't forget the grout and thinset — this tool sizes the tiles; buy adhesive and grout separately based on the coverage on their bags.