Tile Calculator
Work out how many tiles, boxes, and dollars a floor or wall needs from the room size, tile size, and a waste allowance.
🧱 What is a Tile Calculator?
A tile calculator converts a room's dimensions and a tile's size into the number of tiles, boxes, and total cost needed to cover it, after applying a waste allowance for cuts and breakage. Because tile is sold by the piece and packaged by the box, and rooms are rarely an exact multiple of the tile size, this calculation always involves rounding up, both the raw tile count to a whole tile and the box count to a whole box.
This comes up on nearly every flooring, backsplash, and shower job. A homeowner comparing tile options at a store, a contractor pricing a bathroom remodel, and a DIYer ordering material online all need the same answer before they can commit to a purchase: exactly how many tiles, and how many boxes, does this specific room need at this specific tile size.
A common misconception is buying exactly the calculated tile count with no waste allowance. Real installations always lose material to cuts around the room's perimeter, doorways, and fixtures, plus the occasional broken tile, so a 10 to 15 percent waste margin is standard practice, not padding. Another mistake is forgetting to convert tile dimensions from inches to feet before comparing them to a room measured in feet, which this calculator handles automatically.
Enter the room's length and width, the tile's width and length in inches, a waste percentage, and optionally the tiles per box and a price per tile, and the calculator returns the tiles needed, the boxes to buy, and the estimated cost, all shown with the working.
📐 Formula
📖 How to Use This Calculator
Steps
💡 Example Calculations
Example 1 — A Living Room Floor
10 ft by 12 ft room, 12 by 12 inch tiles, 10% waste, 10 tiles per box, $2.50 per tile
Example 2 — A Small Bathroom Floor
8 ft by 6 ft bathroom, 6 by 6 inch tiles, 15% waste, 20 tiles per box, $1.20 per tile
Example 3 — A Kitchen Floor With Large Tiles
15 ft by 10 ft kitchen, 18 by 18 inch tiles, 10% waste, 6 tiles per box, $4.00 per tile
❓ Frequently Asked Questions
🔗 Related Calculators
How do I calculate how many tiles I need for a room?
Divide the room area by the area of one tile, then add a waste allowance and round up. For a 10 by 12 foot room (120 sq ft) using 12 by 12 inch tiles (1 sq ft each) with 10% waste, that is 120 / 1 x 1.10 = 132 tiles, rounded up.
How much extra tile should I buy for waste?
A common rule is 10% extra for a simple straight layout, and 15% or more for a diagonal layout, a room with many corners, or a tile pattern that requires more cuts. This calculator applies whatever waste percentage you enter before rounding up to a whole tile.
How do I convert tile size in inches to square feet?
Divide each tile dimension by 12 to convert inches to feet, then multiply the two together. A 12 by 12 inch tile is (12/12) x (12/12) = 1 square foot, an 18 by 18 inch tile is (18/12) x (18/12) = 2.25 square feet.
How many boxes of tile do I need?
Divide the total tiles needed (after waste, rounded up) by the number of tiles per box, then round up, since you cannot buy a fraction of a box. If you need 132 tiles and a box holds 10, that is 132 / 10 = 13.2, rounded up to 14 boxes.
Why does this calculator round the tile count up rather than down?
You cannot install a fraction of a tile, and rounding down would leave the room short. Rounding up after applying the waste allowance ensures you have enough material to finish the job, including the pieces lost to cuts around edges and fixtures.
How do I measure a room for tile if it isn't a perfect rectangle?
Break the room into rectangular sections, calculate the area of each separately, and add them together before entering the total as your length times width, or simply enter the combined square footage directly by setting length to the total area and width to 1.
Does grout line width affect how many tiles I need?
Grout lines add a small amount to the covered area per tile, but the effect is minor for typical grout widths (1/8 to 3/8 inch) and is generally absorbed within a standard 10% waste allowance. Very wide grout joints on a small tile can justify a slightly higher waste percentage.
What's a typical price per tile for flooring?
Ceramic and porcelain floor tiles commonly run $1 to $5 per tile depending on size, material, and finish, with natural stone and large-format tiles often costing more. Enter your actual price per tile in this calculator to get a project-specific material cost estimate.
Should I order more tile for a bathroom than a bedroom?
Bathrooms and kitchens typically need a higher waste allowance, often 15%, because of cuts around toilets, vanities, cabinets, and appliances, compared to an open bedroom floor where 10% is usually enough. Adjust the waste percentage in this calculator to match the room's complexity.
How do I calculate tiles needed for a wall instead of a floor?
The math is identical, use the wall's height and width (or the tiled area's dimensions) in place of a room's length and width, and enter your wall tile's size. Backsplashes and shower walls often use a higher waste allowance because of cuts around outlets, corners, and fixtures.