How is tile count calculated?

Area × (1 + waste) ÷ (tile length × tile width), then round up to whole tiles. Boxes are ceil(tiles ÷ tiles per box).

Straight vs diagonal layout?

Diagonal (or complex patterns) waste more. Switching layout updates the suggested waste percent; you can still type your own value.

Floor or wall — does it change the math?

The formula is the same. The surface control mainly suggests a default waste percent and helps you remember which plane you are ordering for.

Should I buy extra boxes beyond the result?

Keep a few spare tiles from the same dye lot for future repairs. The waste field already covers cutting; spares are an optional extra box.

What about grout joints?

Joint width slightly reduces coverage per tile. For large formats with narrow joints the effect is small; for mosaic sheets, trust the box coverage chart and raise waste if the room is cut up.

Tiling a shower and a floor?

Run the calculator once per plane or per tile size. Different sizes need separate orders. For painted walls nearby, see [[paint-calculator|Paint calculator]].

Laminate instead of ceramic?

Use [[flooring-calculator|Flooring calculator]] — packs use coverage per carton, not individual tile size.

Calculate how many tiles and boxes to buy

Enter the floor or wall area, tile size, waste percent, and tiles per box. The tool adds waste, divides by one tile’s area, and rounds up to whole tiles and whole boxes so you are not short on the last course.

Units

Area (sq ft)Tile length (in)Tile width (in)Waste %Tiles per boxSurfaceLayout

Results

Area with waste: 110 sq ft

Tiles (exact): 110

Tiles to buy: 110

Boxes to buy: 11

Formula

Area with waste = area × (1 + waste); Tiles = ceil(area with waste ÷ tile area); Boxes = ceil(tiles ÷ tiles per box)

Worked steps (check these)

Tile length×Tile width = 12 in × 12 in → 1 sq ft
Area with waste = 100 × (1+0.1) = 110 sq ft
Tiles (exact) = 110 ÷ 1 = 110
Tiles to buy = ceil(110) = 110
Boxes to buy = ceil(110 ÷ 10) = 11

Estimates only — confirm with product labels and a licensed pro. Not a substitute for structural or roofing advice.

Tile is sold in boxes that rarely match your room area exactly. Running out mid-install is painful: dye lots shift, and a replacement box can look half a shade off under kitchen lights. Ordering a little over with a clear waste percent is cheaper than an emergency drive across town.

Start from a measured area — length × width for a rectangle, or the sum of zones for L-shaped rooms. Enter the nominal tile size from the box; the tool converts edge units so area stays consistent. Then apply waste for cuts at walls, toilets, and cabinets.

Large-format tiles and diagonal layouts throw away more edge pieces. If the room has many niches, bump waste another few percent beyond the default. When you also need a mud bed or thinset pad, pair this page with Concrete calculator for substrate volume.

How to estimate tile

Select units and enter the surface area
Enter tile length and width (inches or centimeters)
Set waste %, tiles per box, surface, and layout
Read area with waste, tiles to buy, and boxes to buy

Why use this tile calculator

Rounds to buyable tile counts and full boxes.
Waste % is visible and adjustable for pattern complexity.
Floor/wall and straight/diagonal presets nudge sensible defaults.
Works for imperial tile inches or metric centimeters.
Shows exact vs rounded quantities so you see the cushion.

Good for

Kitchen or bath floor tile shopping list
Subway tile backsplash with outlet cutouts
Diagonal foyer pattern that needs higher waste
Comparing 12×12 vs 12×24 coverage before ordering
Landlord turnkey baths where extras must stay minimal

Common tile mistakes to avoid

Ordering to exact area with 0% waste — almost every room needs cuts.
Mixing dye lots when you under-order; buy from one lot when possible.
Entering tile size in inches while area is in meters without switching units.
Ignoring niches, hearths, and closet returns that add area outside the main rectangle.
Forgetting that rectified large tiles still need movement joints and extra pieces at borders.

Worked tile examples

Input	Output	Note
100 sq ft area, 12×12 in tiles (1×1 ft), 10% waste, 10 tiles/box, straight layout	Area with waste 110 sq ft; 110 tiles exact → 110 to buy; 11 boxes	tiles=ceil(area×(1+waste)/(tile area)); boxes=ceil(tiles/tilesPerBox)
100 sq ft, 12×12 in, 15% waste (diagonal), 10 tiles/box	Area with waste 115 sq ft → 115 tiles → 12 boxes	Diagonal layouts need extra cuts; raise waste toward 15%
Wall backsplash 30 sq ft, 3×6 in subway, 10% waste, 20 tiles/box	Convert tile edges to feet (0.25×0.5), then ceil tiles and boxes	Mark surface as wall; keep waste at least 10% for cuts around outlets

Tile calculator FAQ

How is tile count calculated?: Area × (1 + waste) ÷ (tile length × tile width), then round up to whole tiles. Boxes are ceil(tiles ÷ tiles per box).
Straight vs diagonal layout?: Diagonal (or complex patterns) waste more. Switching layout updates the suggested waste percent; you can still type your own value.
Floor or wall — does it change the math?: The formula is the same. The surface control mainly suggests a default waste percent and helps you remember which plane you are ordering for.
Should I buy extra boxes beyond the result?: Keep a few spare tiles from the same dye lot for future repairs. The waste field already covers cutting; spares are an optional extra box.
What about grout joints?: Joint width slightly reduces coverage per tile. For large formats with narrow joints the effect is small; for mosaic sheets, trust the box coverage chart and raise waste if the room is cut up.
Tiling a shower and a floor?: Run the calculator once per plane or per tile size. Different sizes need separate orders. For painted walls nearby, see Paint calculator.
Laminate instead of ceramic?: Use Flooring calculator — packs use coverage per carton, not individual tile size.