Tile Calculator
Find how many tiles and boxes to buy for a floor or wall, with waste, grout, thinset and total cost. Free, no sign-up, and it runs in your browser.
Dedicated page: /en/tile-calculator
Default checked 10 Nov 2026: $2.50 per tile (typical glazed ceramic about $1.60 to $3.20 per sq ft; a 12x12 tile is 1 sq ft). Leave it, or enter your exact price if you know it. Check the current value here.
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Quick answer
A tile calculator works out how many tiles, boxes, grout and thinset a floor or wall needs. Enter the area and the tile size, add a waste allowance for cuts, and it rounds up to whole boxes, then estimates the grout and thinset from the area.
About this Tile Calculator
Find how many tiles and boxes to buy for a floor or wall, with waste, grout, thinset and total cost. It is one of the Home and DIY on ToolUstad, and like every tool here it runs entirely in your browser: nothing you type, paste or open is uploaded to a server, and there is no sign-up or usage limit.
What is a tile calculator?
Tiling a floor or a wall is a job where the shopping list matters more than the labour. Tiles are sold by the box, grout and thinset by the bag, and all three come in dye lots and batches that vary slightly, so buying the right amounts in one trip, from one lot, is the difference between a job that looks professional and a job with a visible colour change halfway across the room. The calculator works out the area, divides it by the tile size, adds waste for the cuts around edges and fixtures, and rounds up to whole boxes.
The waste allowance is the part people get wrong. A simple rectangular room laid straight needs about 10% extra for cut tiles at the edges. A diagonal layout needs 15%, because every edge tile is cut at an angle and produces more offcuts. A room with many fixtures, angles or a herringbone pattern needs 15 to 20%. The grout estimate is one 25 pound bag per 100 square feet, and thinset is one 50 pound bag per 50 square feet, which are the standard trade figures.
How does tile maths work?
A 10 by 8 foot bathroom floor is 80 square feet. With 12 by 12 inch tiles, each tile covers 1 square foot, so 80 tiles cover the floor. Add 10% waste and the total is 88 tiles. Tiles come 10 to a box, so 9 boxes are needed, and the spare 2 tiles are kept for future repairs. Grout is one bag for the 80 square feet, and thinset is two bags, because each 50 pound bag covers about 50 square feet. The cost is the tiles at your price per tile, plus about $12 per grout bag and $15 per thinset bag.
When and why to use a tile calculator
- Before ordering tile: buy the whole job from one dye lot, because two lots of the same tile can differ visibly.
- Budgeting a bathroom or kitchen: tile, grout and thinset are three separate costs, and forgetting any one of them breaks the budget.
- Comparing tile sizes: large tiles cover a floor with fewer pieces and fewer grout lines, but they waste more on cuts in small rooms.
- Backsplashes: small areas with many cuts around outlets need the higher waste figure, which this tool lets you set.
- Checking a contractor's quote: knowing the tile count yourself shows whether the quote has padded the materials.
Best practices
- Measure twice and include every alcove and recess: the area under the bath and behind the toilet still needs tiles.
- Buy one spare box beyond the calculation for repairs, because the same tile may not be in stock in two years.
- Dry-lay the first row before mixing thinset, to check the cuts at both ends are not slivers.
Common mistakes to avoid
- Using 0% waste: every real room has edges, and every edge needs a cut tile.
- Forgetting the grout joint: tiles are spaced 1/8 to 1/4 inch apart, so the coverage per tile is slightly less than its face size.
- Buying boxes from two lots: the shade difference is small in the shop and obvious on the floor.
Who is the tile calculator for?
Homeowners tiling a bathroom, kitchen or floor themselves, landlords refreshing a rental, and small contractors pricing a job. It is also used by tile shop staff for quick estimates at the counter.
Current value, checked 10 Nov 2026: the default tile price is $2.50 per tile (typical glazed ceramic about $1.60 to $3.20 per sq ft; a 12x12 tile is 1 sq ft). The price box is an optional override: leave the default, or enter your exact price and the cost uses it.
Learn: how to use the Tile Calculator
- Measure the area in feet: length times width gives the square footage.
- Pick your tile size from the common sizes, or enter a custom size in inches.
- Choose a waste allowance, 10% is standard, then read the tiles, boxes, grout and thinset to buy.
Features
- Common tile sizes from 6 by 6 to 24 by 24 inches, plus custom sizes
- Waste allowance from 5% to 20% for straight, diagonal and complex layouts
- Tiles rounded up to whole boxes
- Grout estimate at one bag per 100 sq ft and thinset at one bag per 50 sq ft
- Total cost from your price per tile, with grout and thinset priced in
Worked example
A 10 by 8 foot bathroom floor, 80 sq ft, with 12 by 12 inch tiles at 10% waste: 80 tiles plus 8 for waste is 88 tiles, which is 9 boxes of 10, plus 1 bag of grout and 2 bags of thinset.
Frequently asked questions
How much waste should I add for tile?
10% for a simple rectangular room with straight laying, 15% for diagonal laying or rooms with many cuts around fixtures, and 5% only for large open rooms with almost no cutting.
Why do I need to round up to whole boxes?
Tile is sold by the box, not by the tile, and dye lots vary between batches. Buying whole boxes from one lot keeps the colour consistent and leaves spares for future repairs.
What size trowel do I need?
A 1/4 by 3/8 inch square notch trowel suits most wall tiles, and a 1/2 by 1/2 inch trowel suits large floor tiles. Your thinset bag states the trowel size for that product.
Can I use this for a backsplash?
Yes. Measure the backsplash area in feet the same way, pick a small tile size like 3 by 6 inch subway tile, and use 15% waste because a backsplash has many cuts around outlets.
How do I measure a room for tile?
Measure the length and width in feet at the longest points, including alcoves, and multiply them. For L-shaped rooms, split the floor into rectangles, measure each, and add the areas together.
What is thinset?
Thinset is the cement-based adhesive that sticks tiles to the floor or wall. It is mixed with water, spread with a notched trowel, and the tile is pressed into it. One 50 pound bag covers about 50 square feet.
Should I seal grout?
Yes, for floors and showers. Grout is porous and absorbs water and stains. Sealer is painted on after the grout cures, usually after 48 to 72 hours, and reapplied every year or two.
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