Tile Calculator

How to use the tile calculator

Measure the area you’re tiling — floor, shower wall, or backsplash — and enter its length and width in feet. For walls, "length" is just the wall’s width and "width" is its height; the math doesn’t care which is which. Irregular spaces break into rectangles: an L-shaped bathroom floor is two runs of this calculator added together, and a kitchen backsplash interrupted by a window is the full rectangle minus nothing — treat the window cutout as part of your waste margin instead of over-engineering the takeoff.

Pick your tile size from the presets or choose Custom and enter the dimensions in inches off the box label. Size changes the count dramatically — the same 88 sq ft order is 88 twelve-inch tiles but 352 six-inch mosaics — which matters for budgeting grout, spacers, and your own patience. Plank-format presets like 12 × 24 are entered exactly as labeled; orientation doesn’t change the area.

Waste matters more with tile than almost any material because every cut piece at a wall edge is usually unusable on the other side, and tile also breaks — in shipping, in cutting, and occasionally in your hands. Ten percent is the standard allowance for straight layouts. Move to fifteen for diagonal layouts, herringbone, large-format tile in small rooms (more cuts per square foot), and natural stone, which chips and shade-varies more than porcelain.

If you know how many tiles come in a box, add it under Advanced and you’ll get a box count rounded up to whole boxes. Like flooring, tile is dye-lotted: buy all your boxes from the same lot number and check each box at pickup, because a lot mismatch shows up as a visible shade band across the finished surface.

Buy your full order before the first tile goes down, and keep the leftovers. A cracked tile five years from now is a twenty-minute fix when you have three spares in the garage and a sourcing nightmare when you don’t. Spares from your own lot are the only guaranteed match.

The formula

Tile math is area-with-waste divided by the area of a single tile — inches converted to square feet by dividing by 144:

tile area (sq ft) = (tile width in × tile height in) ÷ 144
order area = length × width × (1 + waste% ÷ 100)
tiles = order area ÷ tile area, rounded UP to a whole tile
boxes = tiles ÷ tiles per box, rounded UP   (when a box count is entered)

Worked example with the defaults: a 10 × 8 ft floor is 80 sq ft, and 10% waste brings the order to 88 sq ft. A 12 × 12 in tile is exactly 1 sq ft (144 ÷ 144), so you need 88 tiles. If the label says 10 tiles per box, 88 ÷ 10 = 8.8 — buy 9 boxes.

The estimate intentionally ignores grout-line spacing. Grout gaps mean each tile covers slightly more floor than its own area, so real coverage runs a touch better than the math — a small built-in buffer on top of your waste allowance, not a reason to trim the order.

Frequently asked questions

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