Flooring Calculator

What this flooring calculator does

Buying flooring is mostly a counting problem with a few traps in it. You need the real floor area, you need to allow for the boards or tiles you will cut and throw away, and you need to turn all of that into whole boxes, whole tiles, or a length of carpet roll. Get any step wrong and you either stall the job waiting for a second delivery or end up with a stack of boxes you will never open.

This flooring calculator handles all three steps. Enter the room size, or an area you already know, subtract anything the floor will not cover, pick your material, and choose how the floor will be laid. It returns the area to buy, the number of boxes, tiles, or the roll length, how much is left over after rounding, and an optional cost. A top-down layout preview shows how planks, tiles, or carpet strips run across your room, a bar graph shows how the measured area becomes the amount you purchase, and a chart shows how the box count changes at different waste allowances.

If you only need the area of a room first, use the square footage calculator. If you are planning a wider renovation, the paint calculator and sheetrock calculator cover the walls. You can also browse all flooring calculators and painting calculators.

How to calculate flooring needed

Whether you think of it as working out the square footage for flooring or as a quick flooring computation, the steps are the same, and there are four of them:

1. Measure the floor area. For a rectangle, length × width. For an L-shaped or irregular room, split it into rectangles, calculate each, and add them.
2. Subtract what the floor will not cover. Fixed cabinets, a kitchen island, or a built-in hearth do not need flooring under them.
3. Add waste. Multiply the net area by (1 + waste percentage) to allow for cuts and mistakes.
4. Convert to what you buy. Divide by the coverage of one box and round up. For tile, divide by the area of one tile. For carpet, work out the roll length from the roll width.

As a formula: boxes = net area × (1 + waste) ÷ coverage per box, rounded up. A 14 by 12 foot room is 168 square feet. With 8 percent waste that is 181.4 square feet. At 20 square feet per box, that is 9.07 boxes, so you buy 10. The calculator shows the exact figure and the rounded one, so you can see how close you came to the next box.

How much waste to add

Waste covers the cuts at walls and doorways, offcuts too short to reuse, and the occasional damaged board. Guides give slightly different numbers, but they agree on the pattern: a straight lay wastes the least, a diagonal lay wastes more, and herringbone or parquet wastes the most. The table shows the starting points the calculator uses.

These are rules of thumb, not guarantees. Solid hardwood often needs a little more than laminate or vinyl plank, because some boards are set aside for defects, and a small room, a long hallway, or a room with many doorways needs more than a large open one. Whatever the percentage, order every box you need at once, because color and shade can differ between production batches. Keep a box or a few spare boards afterward for repairs.

Laminate flooring calculator notes

If you came for a laminate flooring calculator, the same method applies, with a few laminate-specific points. Laminate is sold by the box, and coverage per box varies by product, commonly somewhere around 18 to 24 square feet, so use the figure printed on your carton. Most laminate is a floating click-lock floor, which usually needs a gap around the room edge for expansion, so follow the manufacturer’s instructions when you measure the usable area. Underlayment is bought separately by area, and it is worth checking whether your product has a pad attached.

Laminate and vinyl plank are easy to cut, so a simple rectangular room can sit near the lower end of the waste range. A hallway, a small room, or a room with many angles belongs near the upper end.

Hardwood and wood floor notes

The same calculator works as a hardwood floor calculator and a wood floor calculator. Solid and engineered wood are usually sold by the box in a coverage that depends on the board width and length, so check the carton. Wood floors can be glued, nailed, or floated, and the manufacturer specifies which methods suit your product. Wood also reacts to humidity, so manufacturers give instructions for storing and acclimating the boards before installation. Follow those for your product rather than a general rule.

When you choose a pattern, remember that a diagonal or herringbone wood floor uses a lot more material than a straight lay, which is why the layout setting changes the starting waste. If you are planning a refinish of an existing floor instead of a new one, this calculator is not the right tool, since you are not buying boards.

Flooring calculator for tile

Choose tile in the calculator to count tiles directly. Pick a tile size and the calculator divides your area with waste by the area of one tile. A 12 by 24 inch tile covers 2 square feet, a 24 by 24 inch tile covers 4, and a 12 by 12 tile covers 1. If you know how many tiles come in a box, enter it and the calculator also gives the number of boxes.

Tile often needs a slightly higher waste allowance than click-lock planks, because a cut tile cannot be trimmed and reused the way a plank end can, and large tiles leave bigger offcuts at the edges of a small room. If you are using a diagonal or a pattern, raise the allowance. This tool counts tiles only. Grout, thin-set, spacers, and backer board are bought separately, and the amounts depend on the tile, the joint width, and the surface.

Flooring calculator for carpet

Carpet is different because it is sold from a roll, in a fixed width, and priced by the square yard or square foot. The calculator turns your area with waste into square yards (square feet ÷ 9) and an estimated roll length for the width you choose, most often 12 or 15 feet. It ignores seams, pattern matching, and the direction of the pile, so treat the length as a starting estimate. For an actual order, a carpet installer will plan how to cut the roll to the room, which can change the length you need. Rooms wider than the roll need a seam, and that is worth checking before you buy.

How many square feet do 40 planks cover?

This is a common question, usually asked by people with an open carton and a row of planks on the floor. The area of one plank is its width times its length, and the answer for any number of planks is that area times the count. The table shows 40 planks at common sizes, using a 48 inch length.

Real planks vary, and tongue-and-groove edges mean the covered width is slightly less than the stated width, so use the coverage printed on the carton when you have it. To go the other way, divide the area you need by the area of one plank and round up.

Flooring cost

If you enter a price per square foot, the calculator multiplies it by the area you buy, not the area you measure. That matters, because you pay for the leftover boxes as well. If you add an installation rate per square foot, it applies to the net floor area and gives a total and a cost per square foot installed. I have deliberately not built in prices. Flooring prices vary widely by material, grade, brand, and region, and any number printed here would be out of date soon. Use your supplier’s price for the exact product, and ask for quotes from installers, since installation, removal of old flooring, underlayment, trims, and subfloor preparation can add up.

Worked examples

Example 1: a living room in laminate

The room is 14 by 12 feet, or 168 square feet. With a straight lay and 8 percent waste, the area to buy is 181.44 square feet. At 20 square feet per box, that is 9.07 boxes, so buy 10 boxes. Ten boxes cover 200 square feet, which leaves 32 square feet beyond the floor itself, enough for the cuts plus about one box of spares.

Example 2: a kitchen in tile

A kitchen measures 10 by 12 feet, which is 120 square feet, and a 15 square foot island does not need tile under it, so the net area is 105 square feet. With 8 percent waste that is 113.4 square feet. In 12 by 24 inch tiles of 2 square feet each, you need 56.7 tiles, so buy 57. Check the tiles per box, and if the box count rounds the order up you may end up with a few extra tiles, which is useful for repairs.

Example 3: a bedroom in carpet

A bedroom is 12 by 15 feet, which is 180 square feet. With 8 percent waste that is 194.4 square feet, or 21.6 square yards. On a 12 foot wide roll, the estimated length is 16.2 feet, which rounds up to 16.5 feet, or 198 square feet. Enter these numbers in the calculator to confirm each step, and ask your installer to confirm the cut.

Common mistakes to avoid

• Ordering the measured area. Without waste you will almost always run short once the cuts are made.
• Forgetting closets, hallways, and alcoves. Add them to the floor area, because they need flooring too.
• Ignoring the carton coverage. Boxes vary from product to product, so check the number on the carton.
• Not rounding up. You cannot buy 0.07 of a box, so take the next whole box.
• Mixing batches. Color can differ between production runs, so buy it all at once.
• Using straight-lay waste for a diagonal or herringbone floor. Those layouts use noticeably more material.
• Mixing units. Entering metres while the unit is set to feet changes the answer by a factor of about ten. Select the unit first.

How this calculator works and what it assumes

The calculator runs in plain JavaScript in your browser, so your measurements are not sent anywhere. It finds the net floor area, adds your waste allowance, divides by the coverage of one box, one tile, or the roll width, and rounds up to a whole unit. Metric inputs are converted at 10.764 square feet per square metre. Results are always shown in square feet.

What it assumes, and what it leaves out:

• The room is a simple rectangle. For an irregular room, add the rectangles yourself and use the total area option.
• Waste values are common rules of thumb. Use your supplier’s advice for your product and layout.
• Box coverage and tile sizes are what you enter. The calculator does not know your specific product.
• Carpet length is an estimate that ignores seams, pattern matching, and pile direction.
• The layout preview is illustrative. It shows planks of about 7 inches, the chosen tile size, or carpet strips of the roll width, and a 45 degree rotation for a diagonal lay. It is not a cutting plan.
• No allowance for underlayment, trim, transitions, grout, adhesive, or subfloor repair.

I am a software engineer, not a flooring installer, so use the result as a planning figure and confirm quantities with your supplier or installer before you order. Change log: October 9, 2026, first published with laminate, hardwood, vinyl plank, tile, and carpet options, a layout preview, a waste chart, and optional cost.

Frequently asked questions

Related calculators: work out the area first with the square footage calculator, plan the walls with the paint calculator and sheetrock calculator, or budget the roof with the roof replacement cost calculator. Browse all flooring calculators and painting calculators.

Sources and further reading

The area and quantity math is basic geometry. For typical waste allowances by layout, see the retailer guides from Oak Parquet and Word of Mouth Floors, which give straight-lay and diagonal or herringbone ranges by material. Those figures differ a little between sources, so treat them as starting points, and always follow your flooring manufacturer’s installation instructions for your product.