Tile Calculator: How Many Tiles Do I Need?
Enter your surface size and tile dimensions for an instant count of how many tiles — and boxes — to buy. Works for floors, walls, and backsplashes of any tile size, with waste for cuts built in.
Tile Calculator
Enter the surface size and your tile dimensions. The calculator tells you how many tiles to buy — for floors, walls, or a backsplash — with waste for cuts included.
How to use this tile calculator
Enter the length and width of the surface in feet, then your tile width and length in inches. Choose the layout — straight, diagonal, or patterned — to set the right waste factor, and optionally add the tiles per box so the calculator rounds up to whole boxes. Press calculate for a clear "buy this many" result.
How much waste should you plan for?
You always cut tiles at the edges, and offcuts often can't be reused. A straight grid layout wastes about 10%, a diagonal layout about 15%, and herringbone or other patterns up to 20% because of all the angled cuts. The extra also leaves you matching spares — invaluable if a tile cracks years later.
Thinset, grout, and the dye-lot rule
Budget roughly one bag of thinset per 40–50 sq ft, more for large-format tile and bigger trowel notches. Grout varies a lot with tile size and joint width. The most important buying tip: get every box from the same lot/shade number — tile color drifts between production runs, and a mismatched box stands out badly on a finished wall or floor.
Floors, walls, and backsplashes
The math is identical for any surface — only the area changes. For a floor, use the room's length and width. For a shower or accent wall, use the wall's width and height. For a backsplash, measure the run of counter by the height of the tiled band. Enter that area and your tile size and you're set.
Frequently asked questions
How many 12×12 tiles do I need for a 10×10 floor?
A 10 ft × 10 ft floor is 100 sq ft. A 12×12 inch tile covers 1 sq ft, so with 10% waste for cuts you would buy about 110 tiles. Larger or smaller tiles change the count, which the calculator handles automatically.
How much extra tile should I buy for waste?
Add about 10% for a standard straight or grid layout, 15% for a diagonal layout, and around 20% for herringbone or other patterns, since angled cuts waste more. Buying a little extra also gives you spares that match your dye lot for future repairs.
How do I calculate tiles of a different size?
Just enter your tile width and length in inches. The calculator converts to square feet (width × length ÷ 144), divides your surface area by it, and adds the waste factor — so it works for mosaics, subway tile, large-format, or anything in between.
How much thinset and grout do I need?
A rough guide is one bag of thinset mortar per 40–50 sq ft, though large or heavy tiles and bigger trowels use more. Grout depends on tile size and joint width — small tiles with wide joints use far more than large tiles with thin joints. Check the bag coverage for your specific setup.
Should I buy full boxes of tile?
Yes — tile is sold by the box, so enter the tiles-per-box figure and the calculator rounds up to whole boxes. Always buy from a single lot/shade number, because color varies between production runs, and keep a spare box for repairs.
Does this work for wall tile and backsplashes?
Yes. Tile is tile — enter the area of any surface you are covering (floor, shower wall, or backsplash) and your tile size. For a backsplash, measure the length along the wall by the height of the tiled band.
Related calculators
Tiling over a new wall? Size it with the drywall calculator. Doing the floor in planks instead? Try the flooring calculator. See all material calculators ›