CalculateItNow home

Tile Calculator

How many tiles and boxes you need for a floor or wall from the area, tile size and grout gap, with a waste factor for cuts and the work shown step by step.

Tile Calculator: with the default inputs, tiles to buy is 44.

ft
in
ft
in
%
Try an example
Tile with any side 15 in or longer (large-format) is usually set with a 3/16-in joint to absorb warpage (TCNA). Check the manufacturer's minimum.
Tiles to buy
44

Includes waste, rounded up.

Tiles before waste
40
Boxes
6
Area to tile
80 ft²
Area of one tile
2 ft²
Tiles per square foot
0.49
Tile cost
$0.00
Assumptions
  • Tiles are laid in a grid; pattern-specific waste is captured only by the waste percentage.
  • Boxes are whole cartons.
Tiles per square foot for common sizes (1/8-in joint)
TilePer ft²Per 100 ft² (+10%)
3 × 6 subway7.52828
4 × 48.46931
6 × 63.84423
12 × 120.98108
12 × 240.4955
18 × 180.4449
24 × 240.2528
6 × 36 plank0.6572
Math verified by automated testsUpdated 2026-09-082 sources cited

How this is worked out

The formula

Tile footprint = (tile width + grout gap) × (tile length + grout gap)
Tiles needed = area ÷ tile footprint
Tiles to buy = tiles needed × (1 + waste %), rounded up
Boxes = tiles to buy ÷ tiles per box, rounded up

Open How it’s calculated above to see this worked through with your own numbers.

What you enter

Area length
A number.in ft, in, m, cm · 0 or more · defaults to 10
Area width
For a wall, use its height.in ft, in, m, cm · 0 or more · defaults to 8
Tile width
A number.in in, cm, mm · 0.1 or more · defaults to 12
Tile length
A number.in in, cm, mm · 0.1 or more · defaults to 24
Grout gap
1/16 in for rectified tile, 1/8 in typical, 3/16–1/4 in for handmade or large-format.in in, mm, cm · from 0 to 2 · defaults to 0.125
Waste factor
10% for a straight or brick layout, 15% diagonal, 20% herringbone or lots of cuts.a percentage · from 0 to 50 · defaults to 10
Tiles per box
Printed on the carton. Set to 1 if buying loose tiles.from 1 to 1000 · whole numbers only · defaults to 8
Price per box(under More options)
Leave 0 to skip cost.in dollars · 0 or more · defaults to 0

What you get back

Tiles to buymain answer
Includes waste, rounded up.
Tiles before waste
Boxes
Area to tile
Area of one tile
Tiles per square foot
Including the grout joint.
Tile cost

What this assumes

  • Tiles are laid in a grid; pattern-specific waste is captured only by the waste percentage.
  • Boxes are whole cartons.

About this calculator

Tile is the one flooring material where the grout joint changes the count. A 12 × 12 tile with a ⅛-in joint actually occupies 12⅛ × 12⅛ in, so 100 sq ft takes 98 tiles, not 100 — and a 3 × 6 subway tile with a 1/16-in joint is closer to 7.7 per square foot than 8. This calculator uses the real footprint, then adds waste for cuts and rounds to whole tiles and boxes.

Measuring the area

Measure the length and width of the floor or the width and height of the wall. For a shower, do each wall and the floor separately and add the tile counts (or sum the areas and enter them as one rectangle). Don't subtract for a toilet flange or a small niche; you'll use that material on cuts.

Choosing the grout gap

  • 1/16 in: rectified (precision-ground) porcelain, glass mosaics.
  • 1/8 in: the standard for most ceramic and porcelain floor and wall tile.
  • 3/16 in: the TCNA minimum for large-format tile (any side 15 in or longer), to hide warpage and lippage.
  • 1/4 in or more: handmade, terracotta, quarry tile.

The gap is small, but on a large floor with small tiles it moves the count by several percent.

Waste

Ten percent covers a straight or offset (brick) layout in a rectangular room. Go to 15% for a diagonal set or a room with lots of jogs and fixtures, and 20% for herringbone, chevron, or large-format tile where a single broken piece is expensive. Breakage in shipping, a bad cut, and a future repair all come out of this allowance — keep leftover tiles from the same dye lot.

Boxes

Tile is sold by the box, and the count per box varies with size: eight 12 × 24 tiles (16 sq ft), ten 12 × 12s, a hundred 3 × 6 subways. Enter the number from your carton so the box count is exact. If you're buying loose tiles or mosaic sheets, set tiles per box to 1 and treat "tiles" as sheets by entering the sheet size as the tile size.

Thin-set, grout and backer board are not included; a 50-lb bag of medium-bed mortar covers roughly 40–50 sq ft with a ½-in notched trowel.

Frequently asked questions

How many 12×12 tiles do I need for 100 square feet?

With a 1/8-in grout joint each tile covers 12.125² = 147 sq in, so 100 sq ft takes 98 tiles. Add 10% waste and buy 108 — usually 11 boxes of 10.

How many 12×24 tiles are in 100 square feet?

About 49 with a 1/8-in joint. With 10% waste that's 54 tiles, or 7 boxes of 8.

How much extra tile should I order?

10% for straight or brick-pattern layouts, 15% for diagonal, 20% for herringbone or large-format. Tile dye lots vary, so buying repair stock later rarely matches.

Do I subtract the area under the vanity or toilet?

No. Tile normally runs under a toilet (it's set on top of the tile) and the few square feet under a vanity are cheaper than running out. Only subtract large built-ins.

Put this calculator on your own site

A working tile, free for any site, with no ads and no sign-up. It resizes to fit wherever you paste it and updates itself as this page improves.

Paste this anywhere. It works on any site, carries no ads, never expires, and always shows the current version.

Tile Calculator by CalculateItNow

The page's own title. The clearest description of what the link leads to.

The credit line sits outside the widget on purpose, so it is a real link on your page rather than one buried in a frame. Please keep it — it is what pays for CalculateItNow staying free and ad-free. The script only resizes the widget to fit its contents; drop it and the widget still works.

Browse every calculator widget·How to add it to WordPress, Squarespace or Wix

The questions people ask next to a tile.

All construction & diy calculators·Browse everything