How do I calculate how many tiles I need?

Find the floor area in square feet, add 10% for cuts and breakage, then divide by the area of one tile. A 12 by 10 foot room is 120 square feet, 132 with 10% extra. A 12 by 24 inch tile covers 2 square feet, so you need 66 tiles.

How much extra tile should I buy?

Buy 5% to 10% extra for a straight layout, 15% for a diagonal layout and 15% to 20% for herringbone or patterned tile. Add more for small rooms with many cuts, and keep a few spare tiles for repairs because dye lots can differ later.

How many boxes of tile do I need?

Divide the area with extra by the square feet printed on one box and round up. With 132 square feet and boxes of 15, that is 8.8, so 9 boxes. Tile is sold by the full box, so you will usually have some left over.

Does this work for laminate, vinyl plank and hardwood?

Yes. Enter the width and length of one plank in inches and the coverage per box, and the calculator returns pieces and boxes. Plan for 5% to 10% extra for planks laid straight and more for diagonal layouts or rooms with many angles.

Should I subtract cabinets and islands?

Subtract an island or permanent cabinets that sit on the floor, since you will not tile under them. Do not subtract appliances you may replace, such as a refrigerator or a dishwasher. Tile under a doorway is part of the floor.

Why is my tile smaller than the size on the box?

Sizes on the box are nominal. Under the ANSI A137.1 standard for ceramic tile a real tile can differ slightly from its label, and rectified tile is cut to a tighter size. Grout joints also take space, so the extra percentage absorbs the difference.

How do I measure a room that is not a rectangle?

Split it into rectangles, measure each and add them with the square footage calculator, which also handles L-shapes, triangles and circles. Then switch this calculator to the area option and enter the total.

🏠 Home & Garden

Tile & Flooring Calculator · How Many Tiles and Boxes Do You Need?

Running out of tile halfway through a floor is a headache, because a new batch can differ in shade and the style may be discontinued. Buying far too much wastes money. This calculator turns the size of your room and the size of your tile or plank into the number of pieces and the number of boxes to buy, with an allowance for cuts and breakage.

Enter the room length and width in feet, or the area if you already know it, and subtract anything the floor will not cover, such as a kitchen island or built-in cabinets. Then enter the width and length of one tile or plank in inches. A 12 by 24 inch tile is 12 wide and 24 long. Choose how much extra to add: about 10% for a straight layout, 15% for a diagonal one and up to 20% for herringbone. If you also enter the coverage printed on the box, the calculator counts full boxes and shows how much you will have left over.

It works for ceramic and porcelain tile, stone, laminate, vinyl plank and engineered or solid hardwood, since all of them are bought by the square foot or the box. Tile sizes on the box are nominal, real pieces are often slightly smaller and grout joints take space, which the extra percentage covers. Prices are examples you should replace with the price at your store.

What Do You Know?

Room Length (feet)

For an L-shaped room, use the area option and the square footage calculator

Room Width (feet)

Standard: 10

Area to Subtract (square feet)

Kitchen island, built-in cabinets, a tub or anything the floor will not cover

Tile or Plank Width (inches)

Nominal size from the box. A 12 × 24 tile is 12 wide and 24 long

Tile or Plank Length (inches)

Standard: 24

Extra for Cuts and Breakage (%)

5% to 10% for a straight layout, 15% for diagonal, 15% to 20% for herringbone

Coverage per Box (square feet)

Printed on the box. Needed to count full boxes

Price per Square Foot ($)

Example price only. Check your store

Room size:

Tile size:

Layout:

Detailed Breakdown

9 metrics

PRIMARY RESULT

66 pieces

Tiles or Planks Needed (With Extra)

Area to Cover

120.00 square feet

Area With 10% Extra

132.00 square feet

Size of One Piece

2.00 square feet (12 × 24 in)

Pieces Without Extra

60 pieces

Boxes to Buy

9 boxes

Coverage of Those Boxes

135.00 square feet

Left Over After Installing

15.00 square feet

Material Cost (Full Boxes)

$540.00

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exploreReal-World Scenarios

When to Use This Calculator

Everyday financial situations where this tool gives you fast, accurate clarity:

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Tile a Bathroom or Kitchen

Get the pieces and boxes for a floor, with cabinets and islands subtracted.

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Buy Laminate or Vinyl Plank

Enter the plank size and the coverage per box to count full boxes.

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Plan a Diagonal or Herringbone Layout

Raise the extra percentage for patterns that need more cuts.

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Budget the Material

Add a price per square foot to see the cost of the full boxes.

Calculation Formula

Standard Method

Area to cover = Length × Width − Area to subtract Area with extra = Area × (1 + Extra %) One piece (sq ft) = Width (in) × Length (in) ÷ 144 Pieces needed = Area with extra ÷ One piece, rounded up Boxes to buy = Area with extra ÷ Coverage per box, rounded up Left over = Boxes × Coverage per box − Area to cover Material cost = Square feet in the full boxes × Price per square foot Suggested extra: 5% to 10% for a straight layout, 15% for a diagonal layout, 15% to 20% for herringbone or patterned tile, and more for small rooms with many cuts. Flooring is sold in full boxes, so the cost is based on the boxes you buy, not on the exact area.

Benchmark Example:

A 12 ft by 10 ft room with 12 by 24 inch tile, 10% extra, boxes of 15 sq ft at $4 per square foot: • Area to cover: 12 × 10 = 120 square feet • With 10% extra: 132 square feet • One tile: 12 × 24 ÷ 144 = 2 square feet • Pieces: 132 ÷ 2 = 66 tiles (60 without the extra) • Boxes: 132 ÷ 15 = 8.8, so 9 boxes covering 135 square feet • Left over: 135 − 120 = 15 square feet • Cost: 135 × $4 = $540 The same room laid on the diagonal needs 15% extra: 138 square feet, 69 tiles and 10 boxes (9.2 rounds up). A 10 by 10 foot room with 18 by 18 inch tile on the diagonal needs 100 × 1.15 = 115 square feet, and 115 ÷ 2.25 = 52 tiles.

Frequently Asked Questions

7 answers

Applicable Laws & Regulatory Standards

Tile Council of North America, ANSI & U.S. Environmental Protection Agency

Official Legal Reference

ANSI A137.1 — American National Standard Specifications for Ceramic Tile

Defines the sizes, tolerances and quality grades of ceramic tile. It is why a nominal size on the box can differ slightly from the real tile, a difference the extra percentage in this calculator absorbs.

ANSI A108/A118 — American National Standards for the Installation of Ceramic Tile

Set out the methods and materials for installing tile, including joint widths and layout, which affect how many cuts and spare tiles a job needs.

TCNA Handbook for Ceramic, Glass, and Stone Tile Installation

The industry reference for installing tile on floors and walls, including substrate preparation, which is not part of this quantity estimate and should be checked before you buy.

40 CFR Part 770 — Formaldehyde Emission Standards for Composite Wood Products

Limits formaldehyde emissions from composite wood products sold in the United States, which covers laminate flooring and engineered wood, two of the materials this calculator can be used for.

Legal citations and statutes are provided for consumer transparency, analytical validation, and educational reference under U.S. consumer financial regulations. This tool is not a substitute for formal legal, accounting, or tax counsel.

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