Flooring and tile calculator

How to work out how many boxes of flooring or tile to buy in five steps

1. Measure each room. Measure the length and width of every room, closet or hallway you plan to cover, and add one row for each. Use feet, or switch to meters. The calculator adds the rooms together for you.
2. Type what one box covers. Check the box or the product sheet for how much floor one box covers, in square feet or square meters, and type it in. There is no default, because the number changes from one product to the next.
3. Pick the layout. Choose straight, which adds 10 percent, or diagonal, which adds 15 percent. If you or your installer have a different number in mind, type your own waste percentage instead.
4. Read the result. You see the total area, the area to buy with waste, the number of boxes rounded up, the area you actually bring home and the leftover. If you know the price of one box, type it to see a cost range.
5. Compare bids and print. Enter the bids you were given to see each one per square foot, then print a one-page sheet in English, Spanish or both to take to the store or hand to an installer.

What this calculator does, and what it does not

This page turns the size of your rooms into a number of boxes. You add the rooms, type how much one box covers and choose a layout. Everything is an estimate based on the numbers you type.

It does not look at your floor. It cannot tell you what material to pick. For that, read the product sheet and ask your supplier.

Measuring each room and adding them up

Measure the longest length and the longest width of each room, then multiply them to get its area. A room that is 12 feet by 15 feet is 180 square feet. Do this for every room, closet or hallway that will get the same floor, then add the areas together.

If a room is not a plain rectangle, split it into rectangles, measure each one and add a row for each piece. An L-shaped room becomes two rows. Measure wall to wall.

Why you buy more than the floor area

If you bought only the area of the floor, you would probably run short. Pieces get cut to fit along walls, around corners and at doorways, and the cut-off bit is often too small to use. Some pieces arrive chipped. When a floor has a pattern, the pieces also have to be matched, and that uses extra material too.

That extra material is called waste, and it is added as a percentage of the floor area. A common starting point for a straight layout is 10 percent. Treat 10 percent as a starting point you can change.

Straight, diagonal and herringbone layouts

In a straight layout the pieces run parallel to the walls. Cuts happen mostly at the ends of each row. In a diagonal layout the pieces run at an angle, so almost every piece along every wall has to be cut at an angle, and more cut-offs end up in the bin. This calculator uses 15 percent for diagonal.

Herringbone and other patterns that need careful matching can use even more, because every piece has to line up with its neighbors. For those, type your own waste percentage. Ask your installer or supplier which number they use, then enter it in the custom box.

Worked examples

Straight layout. A room of 200 square feet, a box that covers 20 square feet and 10 percent waste. The area to buy is 200 times 1.10, which is 220.0 square feet. Divide by 20 and you get a whole 11 boxes, so you order 11.

Two rooms, diagonal. One room is 12 by 15 feet, which is 180 square feet. The other is 8 by 10 feet, which is 80 square feet. Together that is 260 square feet. A box covers 23.8 square feet, and diagonal adds 15 percent. The area to buy is 260 times 1.15, which is 299.0 square feet. Divide by 23.8 and you get about 12.563, which rounds up to 13 boxes. Thirteen boxes cover 309.4 square feet, so about 49.4 square feet is left over.

Metric. A room of 4.5 by 3.2 meters is 14.4 square meters. A box covers 2.2 square meters and the waste is 10 percent. The area to buy is 15.84 square meters. Divide by 2.2 and you get 7.2, which rounds up to 8 boxes. Eight boxes cover 17.6 square meters, so 3.2 square meters is left over.

Boxes are whole units, so there is usually a leftover

Flooring and tile are sold by the box, and a store will not split one. That is why the calculator always rounds the number of boxes up.

The leftover is the area you bring home minus the area of the floor. It includes the planned waste and the rounding gap.

Keeping a little extra for future repairs

Many people keep a few spare pieces after the job. A plank gets scratched, a tile cracks, and years later you want to swap it out. The trouble is that products are made in batches, called lots, and a box bought later can differ slightly in color or shade from the box you used. Pieces from the same lot match each other closely.

So when you order, think about whether a leftover box or a part of one is useful to you, and buy it in the same order as the rest. Check the box for the lot number, and ask your supplier whether all your boxes can come from one lot.

Tile, plank and what the numbers leave out

Tile and plank both come by the box. Tile has joints and grout lines that are part of the layout. Plank pieces are long and often run in staggered rows, so the cut-off from the end of one row may start the next. Either way, the box tells you how much floor it covers, and that is the number you type.

This calculator covers the flooring or tile itself and nothing else. It does not include the subfloor, any preparation or leveling of the surface, underlayment, adhesive, grout, trim, transitions or removal of the old floor. Those are separate items, so ask your supplier or installer about each one.

How to read a contractor's quote per square foot

Many installers quote by the square foot. Before you compare two quotes, find out which area the number is based on. One may use the area of the floor and another the area with waste, and they are not the same number. Ask what is included: the material, the labor, removal of the old floor, preparation, underlayment, trim and cleanup.

The bid comparison on this page lets you enter each total and the floor area, and it shows each bid per square foot. Use the same floor area for every bid so the numbers line up. If one bid is far from the rest, a different list of what is included is a common reason, so ask each contractor to write it down.

Privacy

The calculator runs in your browser. The rooms, the box coverage, the prices and the bids you type stay on your device and are not sent anywhere. We do not ask for a phone number, an email or an address, and there is no account to make.

Frequently asked questions