Calculators · 05 of 05

Tile Calculator.

Enter the room size and tile size. Set the grout gap and waste percentage. The calculator returns the tile count, and if you enter tiles per box, the box count too.

  • Imperial & metric
  • Grout gap presets
  • Adjustable waste
  • Box count

The formula

How tile count is calculated

Divide the room area by the area of a single tile (including grout gap on two sides), then multiply by a waste factor and round up.

  1. Measure the room

    Enter length and width in feet (or meters). The calculator multiplies them for room area.

  2. Enter tile size

    Length and width of a single tile in inches (or centimeters).

  3. Set grout gap

    Pick a preset (1/16 in, 1/8 in, 3/16 in, or 1/4 in) or type a custom value. The gap is added to both tile dimensions to get the effective tile footprint.

  4. Set waste percentage

    10% is standard for straight lays. 15% for diagonals. Up to 20% for complex patterns or fragile tile.

  5. Get the count

    The calculator divides room area by effective tile area, multiplies by the waste factor, and rounds up.

Worked examples

Three tiling jobs

Room size and tile size in, tile count out. Waste percentage is the variable that catches people off guard.

Example 01

Bathroom floor, 12 × 12 in tile

Room: 8 × 6 ft. Tile: 12 × 12 in. Grout gap: 1/8 in. Waste: 10%.

Walk-through

Room: 8 × 6 = 48 sq ft = 6,912 sq in
Effective tile: (12 + 0.125)² = 147.02 sq in
Tiles: ⌈(6,912 ÷ 147.02) × 1.10⌉ = 52 tiles

Result 52 tiles

Example 02

Kitchen backsplash, 3 × 6 in subway tile

Area: 3 × 15 ft (45 sq ft). Tile: 3 × 6 in. Grout gap: 1/16 in. Waste: 10%.

Walk-through

Room: 45 sq ft = 6,480 sq in
Effective tile: (3.0625)(6.0625) = 18.57 sq in
Tiles: ⌈(6,480 ÷ 18.57) × 1.10⌉ = 384 tiles

Result 384 tiles

Example 03

Large-format floor, 24 × 24 in porcelain

Room: 14 × 18 ft. Tile: 24 × 24 in. Grout gap: 1/8 in. Waste: 15% (diagonal lay).

Walk-through

Room: 252 sq ft = 36,288 sq in
Effective tile: (24.125)² = 582.02 sq in
Tiles: ⌈(36,288 ÷ 582.02) × 1.15⌉ = 72 tiles

Result 72 tiles

When you'd use this

Five reasons to calculate tile count

Ordering the right quantity saves money and avoids delays.

  • Floor tiling

    Calculate the exact tile count for a bathroom, kitchen, or entryway before placing the order.

  • Backsplash projects

    Subway tile, mosaics, or large format. Enter the wall area instead of floor area, and the math is the same.

  • Waste budgeting

    Cuts, breakage, and pattern matching all consume tiles. The adjustable waste slider lets you plan for it.

  • Box ordering

    Tile ships in boxes. Enter tiles per box and get the box count so you know exactly how many to order.

  • Comparing tile sizes

    Run the calculator with different tile dimensions to see how tile count and box count change. Larger tiles mean fewer pieces but often more waste on cuts.

Conversion reference

Tiles needed per square foot at common tile sizes (no waste, no grout gap). Add 10 to 15% for actual orders.
Tile size (in) Tiles per sq ft Tiles per 100 sq ft
4 × 4 9.00 900
6 × 6 4.00 400
12 × 12 1.00 100
12 × 24 0.50 50
18 × 18 0.44 44
24 × 24 0.25 25

Frequently asked

Tile calculator questions

The questions that come up when ordering tile.

How much extra tile should I order for waste?
10% for a standard straight lay on a simple rectangular room. 15% for diagonal patterns or rooms with many cuts (around pipes, corners, or irregular walls). 20% if the tile is fragile, expensive, or hard to reorder.
Does the grout gap change how many tiles I need?
Yes, but slightly. A wider grout gap means each tile's effective footprint is larger, so you need fewer tiles. On a 100 sq ft floor with 12 × 12 in tile, switching from 1/16 in to 1/4 in grout saves about 4 tiles. The calculator handles this automatically
How do I calculate tile for walls instead of floors?
The same way. Enter the wall height as the "length" and the wall width as the "width." The math is identical: area divided by tile area. For a backsplash, measure just the area you are tiling, not the full wall.
Should I order extra boxes beyond the waste percentage?
If the tile is a natural product (stone, some porcelains) where color varies between production lots, order all boxes at once from the same lot. If the tile is discontinued or imported with long lead times, keep 2 to 3 extra tiles for future repairs. The