Tile Calculator

Take the area you're tiling in square feet, add a waste allowance for cuts and breakage, then divide by the square footage of one tile. A 12 by 12 inch tile is exactly 1 square foot, so a 120-square-foot floor with 10 percent waste needs 132 tiles. This tile calculator runs that math the second you type, so you'll know the count and the boxes before you head to the store.

Multiply the tile's width and height in inches, then divide by 144 to get its area in square feet, and 1 divided by that is tiles per square foot. A 12 by 12 tile is 144 square inches, so 1 square foot, which means 1 tile per square foot. A 6 by 6 tile is 0.25 square foot, so you'll fit 4 per square foot. The calculator shows this figure for whatever size you enter.

Ten percent is the standard cushion for a straight layout, and it covers cuts, edges, and the odd cracked tile. Bump it to 15 percent for a diagonal or herringbone pattern, since angled cuts waste more, and go to 20 percent for a busy room with lots of corners. Some folks call this the overage, but it's the same thing, extra tile so you don't run short mid-job. The waste box above defaults to 10, so you can dial it to match your pattern.

Measure the room in feet and multiply length by width, so a 10 by 12 room is 120 square feet. For the tile itself, multiply its width and height in inches and divide by 144, since a square foot holds 144 square inches. That means a 12 by 12 tile covers 1 square foot, while an 18 by 18 covers 2.25. Divide the room's square footage by one tile's, add your waste, and that's the count. Our square footage calculator handles odd-shaped rooms if you need to add a few rectangles first.

It varies by tile size, but a box of 12 by 12 tiles usually holds 10 to 15, while large-format 24 by 24 tiles often come 3 or 4 to a box. The box always lists the square footage it covers, so check the label and type that count into the tiles-per-box field. Then you'll get the exact number of boxes to buy, rounded up so you don't come up short.

Yes, and the waste percentage handles most of it, but it's smart to keep one spare box too. Dye lots shift between production runs, so a box bought a year later might not match. Tucking away a few tiles from the same lot means a future repair blends in. Round up to whole boxes, which the calculator already does for you.

It does. Measure the wall area the same way, length times height in feet, then enter your tile size and waste. A backsplash or shower wall uses the exact same tiles-per-area math as a floor. For odd shapes, add up the rectangles and tile the total, or use the square footage calculator first to nail down the area.