Surfaces & finishes · free tool

Tile Calculator

How many tiles do you need? Enter your area, pick your tile and layout, and get the exact tiles and boxes to buy — with waste built in.

Free · no sign-up Tiles & boxes Pattern waste built in Floor, wall & backsplash

Tile Calculator

How many tiles & boxes you need — with waste.

1 /ft² EST · US

1 Your project

Tile size
Area you are covering
Grout joint
Layout pattern · sets waste
Waste allowance
10%

2 Your estimate

Tiles
130
Boxes
13boxes
incl. 10% waste

Order 13 boxes — keep a spare box for future repairs.

Area
120 ft²
Coverage
1 /ft²
Waste
10 %
Thinset mortar (50-lb bags)
2bags
Backer board
8 x 3x5 sheets
Grout (est)
8 lb

Estimates only — thinset varies with trowel size (~95 sq ft per 50-lb bag at a 1/4 in notch), grout with tile size and joint. Add spacers and check each bag's coverage.

$
Estimated tile cost
$0
tile only — before grout, thinset, tax & delivery

Estimates only — tile sizes, joints and layout waste vary; confirm the box coverage before ordering. See how we calculate · Updated monthly

Method · how it works

How to calculate how many tiles you need

Area, divided by the coverage of one tile, plus a little waste. Here is exactly what the calculator does, so you can check it by hand.

1

Measure the area

Multiply length × width in feet. For odd rooms, split into rectangles and add them up.

area = L × W
2

Find one tile's coverage

Tile W × H in inches, ÷ 144 = square feet per tile. A 12x12 covers 1 sq ft.

tile ft² = W × H ÷ 144
3

Divide, then add waste

Area ÷ tile size, then +10% for cuts (15% diagonal, 20% herringbone).

tiles = area ÷ tile × 1.10
4

Round up to boxes

Divide tiles by the tiles per box and round up — buy whole boxes from one batch.

boxes = tiles ÷ per box
Worked example

A 100 sq ft floor, 12x12 tile

100 ÷ 1 ft² = 100 tiles
100 × 1.10 = 110 tiles
110 ÷ 10 per box = 11 boxes
Order about
110tiles11boxes

straight lay, 10% waste in

Sources: Tile Council of North America · manufacturer coverage charts · trade waste-factor references

Verified against published tile coverage tables · Updated monthly

Estimates only. The calculator also allows for the grout joint, so it may differ by a few tiles from the simple formula. Tile sizes, box counts and layout waste vary — confirm the box coverage, and order from a single batch so colours match.

Coverage · by tile size

How many tiles per square foot?

Bigger tiles cover more, so you need fewer. These are the common sizes — pick yours in the calculator above, then add waste.

12 x 12
1/ft²

The classic floor tile — one tile per square foot.

Most common
12 x 24
0.5/ft²

Large-format plank look — fewer tiles, fewer joints.

Popular now
18 x 18
0.44/ft²

Roomy floor tile; about 45 per 100 sq ft.

Floors
24 x 24
0.25/ft²

Big-format — four tiles cover a square yard.

Modern
6 x 6
4/ft²

Small floor and wall tile; four per square foot.

Walls
Subway 3 x 6
8/ft²

Classic backsplash tile — eight per square foot.

Backsplash
4 x 4
9/ft²

Small accent and backsplash tile; nine per square foot.

Accent

These are nominal counts — the grout joint trims a little off, and you should always add 10–20% waste on top.

Waste · by layout

How much extra tile to order

Every job needs spare tile for cuts, breakage and future repairs. How much depends on the layout — the calculator sets it for you when you pick a pattern.

Straight lay
10%

Standard grid, tiles square to the walls. The least waste — most cuts happen only at the edges.

Diagonal
15%

Tiles turned 45°. Every perimeter tile is a diagonal cut, and the triangular offcuts rarely reuse.

Herringbone
20%

Angled zig-zag. The most cutting of any common layout — order the most spare here.

Rule of thumb: 10% straight, 15% diagonal, 20% herringbone or intricate patterns. Add a little more for large rooms with lots of corners — and always keep a full spare box from the same batch, since dye lots change between production runs.

Beyond the tile

Grout, thinset & backer board

Tile is only part of the shopping list. Here is what else a job needs and roughly how much — the calculator's Materials tab estimates these from your area.

Thinset mortar~95 ft²/bag

Bonds tile to the substrate. One 50-lb bag covers about 95 sq ft at a 1/4 in notch trowel — larger tiles and notches use more.

Groutvaries

Fills the joints. Amount depends on tile size and joint width — small mosaics use far more than large-format tile. Sanded for joints over 1/8 in.

Backer board15 ft²/sheet

A solid, waterproof base that stops cracking. Cement board comes in 3 x 5 ft sheets (15 sq ft) in 1/4 in and 1/2 in.

Spacersby joint

Keep an even grout line. Pick the width to match your look — 1/16 to 1/4 in — and never butt tiles tight against each other.

These are estimates — always check the coverage printed on each bag, which changes with trowel size, tile format and joint width. Need just the grout or thinset figure? A dedicated grout & thinset calculator is on the way.

Pick your tile

Tile sizes and where they work

Size drives both the look and the count. Larger tiles read calmer with fewer grout lines; smaller tiles suit walls, curves and detail.

12 x 121/ft²

The all-purpose floor tile — simple math (one per sq ft) and easy to lay.

12 x 240.5/ft²

Today's go-to floor look — large, plank-like, fewer seams. Needs a flat substrate.

18 x 180.44/ft²

A roomy square for open floors — fewer joints than 12x12, still easy to handle.

24 x 240.25/ft²

Large-format, modern and seamless — best over very flat floors with the right thinset.

Subway 3 x 68/ft²

The classic backsplash and shower-wall tile — brick-lay, stack or herringbone.

6 x 241/ft²

Wood-look plank tile — runs long and narrow for a flooring-board effect.

4 x 49/ft²

Small accent and backsplash tile — great for borders, niches and retro looks.

Mosaic sheetsby sheet

Small tiles mesh-mounted on ~12x12 sheets — count by the sheet; uses the most grout.

Floor vs wall: heavier, larger tiles suit floors; lighter, smaller tiles suit walls and backsplashes. Not sure of your area? Use the square footage calculator first, then bring the total here.

Answers

Tile calculator FAQs

How many tiles are in a square foot?

A 12x12 is 1 per sq ft; a 6x6 is 4; a 3x6 subway is 8; a 12x24 is 0.5. Divide 144 by the tile's width x height in inches.

How many tiles do I need for a 10 x 10 room?

100 sq ft in 12x12 tile is 100 tiles, or about 110 with 10% waste. Larger tiles need fewer — a 12x24 would be about 55.

How much extra tile should I buy for waste?

10% for a straight lay, 15% diagonal, and 20% for herringbone or busy patterns. Always keep a full spare box for repairs.

How many tiles come in a box?

It varies by size and maker — roughly 10–12 for 12x12, 4–6 for 24x24, and 20–40 for subway tile. Check the box's square-foot coverage.

Do I subtract cabinets, islands or fixtures?

Yes — only tile the floor you can see, so subtract the footprint of cabinets and islands. For walls, subtract windows and large fixtures.

Why does diagonal or herringbone need more tile?

Angled layouts cut every perimeter tile on a diagonal, and the triangular offcuts usually can't be reused — so a herringbone room eats 8–10% more than a straight lay.

What is the grout joint or spacing?

The gap between tiles that grout fills, usually 1/16 to 1/4 in. The calculator folds it into each tile's footprint, so the count is order-ready.

Do I need backer board under tile?

For floors and wet walls, yes — cement backer board (3 x 5 ft sheets) gives a stable, water-resistant base that stops the grout and tile from cracking.