Tile Calculator: how many tiles do you need?

Tile Calculator

This calculator counts the tiles for your job: tiles needed = your area × (1 + wastage) ÷ the area one tile covers, rounded up to a whole tile. Enter the area to tile, your tile’s length and width, and a wastage allowance (10% is the default, and the range our bathroom guide advises is 10–15% for cuts and waste). Example: an 80 sq ft bathroom floor in 12×24 in tiles at 10% wastage needs 44 tiles. It counts tiles only, for what the tilework costs installed, see our Bathroom Remodel Cost guide.

The formula, in full

Tiles needed = ⌈ Area × (1 + Wastage %) ÷ Tile area ⌉, where Tile area (sq ft) = (Tile length in inches × Tile width in inches) ÷ 144.

  • Area, the surface you’re tiling, in square feet: length × width for each wall or floor section, added together.
  • Wastage %, extra tile for cuts, breakage and spares. The calculator defaults to 10% and accepts 0–30%. Our Bathroom Remodel Cost guide advises adding 10–15% for cuts and waste, use the top of that range for diagonal layouts, small rooms with many cuts, or tile you’re matching to a pattern.
  • Tile area, one tile’s face, converted to square feet (144 sq in = 1 sq ft). The count treats the tile’s face size as its coverage; grout joints are not deducted, and in practice the wastage allowance absorbs the difference.
  • ⌈ ⌉ (round up), tiles are whole objects. The calculator always rounds the final count up, and its result line shows the tile area including wastage so you can check the maths.

What the calculator does not do: it doesn’t lay out a pattern or count edge cuts tile-by-tile, and it returns a tile count, not boxes, divide the count by the tiles-per-box figure on the packaging and round up to get boxes.

Tile sizes and coverage

Tile size (inches) Coverage per tile (sq ft) Tiles per sq ft (before wastage)
3 × 6 (subway) 0.125 8.00
4 × 4 0.111 9.00
6 × 6 0.25 4.00
12 × 12 1.00 1.00
12 × 24 2.00 0.50
18 × 18 2.25 0.44
24 × 24 4.00 0.25

Source: computed from tile dimensions, coverage is exact geometry (length × width ÷ 144), the same arithmetic the calculator uses. Checked October 2026.

Worked example: an 80 sq ft bathroom floor, 12×24 in tiles

  1. Tile area: 12 × 24 = 288 sq in ÷ 144 = 2.00 sq ft per tile.
  2. Area with wastage: 80 sq ft × 1.10 (10% wastage) = 88 sq ft of tile.
  3. Tiles needed: 88 ÷ 2.00 = 44 tiles, already a whole number, nothing to round up.

That is exactly what the calculator returns for those inputs: about 44 tiles for 80 sq ft including 10% wastage (88 sq ft of tile). Keep a few of those spares after the job, a discontinued tile is unmatchable later.

Tile calculator FAQ

How many tiles do I need for a 30 sq ft backsplash?
With standard 6×6 in tiles (0.25 sq ft each) and the calculator’s default 10% wastage: 30 × 1.10 = 33 sq ft of tile, and 33 ÷ 0.25 = 132 tiles. Small tiles multiply fast, the same 30 sq ft in 12×12 tiles needs 33 tiles. (Counts checked October 2026.)

How much extra tile should I add for waste?
The calculator defaults to 10% wastage, and our bathroom remodel guide advises 10–15% for cuts and waste (costs and guidance checked October 2026). Straight layouts in open rooms sit at the bottom of that range; diagonal layouts, patterned tile and cut-heavy small rooms belong at the top. The wastage field accepts 0–30%.

Does the calculator count boxes of tile?
No, it returns a tile count. Tile is sold by the box, so divide the count by the tiles-per-box (or sq-ft-per-box) figure printed on the packaging and round up to whole boxes. The worked example above, 44 tiles for an 80 sq ft floor in 12×24 in tile at 10% wastage, is the count you’d take to that packaging figure.

Does the count allow for grout joints?
The calculator treats each tile’s face size as its full coverage and does not deduct grout joints; the wastage allowance (10% by default) is what covers joints, cuts and breakage in practice. If you’re setting wide joints with small tile, nudge the wastage field up rather than doing joint maths by hand.

What will the tile cost for a bathroom remodel?
This page counts tiles; installed pricing lives in our Bathroom Remodel Cost guide, where the tile and waterproofing line for a full remodel, about 140 sq ft of tile across the tub/shower surround and floor, runs $2,000–$4,200 installed (costs checked October 2026). The same guide prices the floor-only tile option in a refresh at the high end of its $300–$1,000 flooring line.

How we estimate

This calculator is a quantity tool, every number it produces is geometry, shown in full above, not a price. Where HomeCostOwl publishes prices, as in the guides this calculator is embedded in, they are built with our Component-Built Cost Method, ranges assembled from the job’s components at verifiable prices and checked against at least three published sources. Full method: How We Estimate.

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