Work out tile boxes, thin-set and grout for floors and walls, with the waste allowance included.
Quick answer: Tile estimating is area plus a waste allowance. A 100 sq ft bathroom floor with 10 percent waste needs 110 sq ft of tile, which is 11 boxes if each box covers 10 sq ft. Box coverage varies by tile size and brand, so check the box, and buy every box from the same batch to match dye lots.
How do you want to enter the area?
sq ft
sq ft
Common boxes cover 8–16 sq ft — the number is printed on the carton.
%
Cutting waste is normally 5–10%; diagonal layouts need 15%.
$
Boxes vary from about $25 to $120 depending on material and finish.
Tile to order
22
boxes
Estimated material cost
$990
200 sq ft + 10% waste = 220 sq ft
Also on the shopping list
Thinset mortar4 × 50 lb bags (typical coverage 60–70 sq ft per bag)
Grout3 × 10 lb units (varies with tile size and joint width)
Spacers & levelling clips55 clips or spacers
Ordering one extra box beats a mid-job shortage: dye lots, tile calibre and wallpaper print runs change between batches, so a later top-up may not match what you already installed.
Every coverage figure here is typical, not exact: box sizes, sheet sizes, roll widths and bag yields change between brands. Check the label on the product you actually buy and round up — a second trip costs more than a spare box.
Core facts
Waste allowance
10% standard, 15% for diagonal layouts
12×12 tile
1 sq ft per tile
Thin-set coverage
roughly 60–70 sq ft per 50 lb bag, typical
Box coverage
varies by tile size and brand
What is Tile Calculator?
Tile is priced and sold by the box, and the number of square feet in a box changes with tile size, thickness and brand. Large-format tiles usually come two or three to a box, while small mosaics can arrive as a dozen or more sheets. That is why an honest tile estimate works in square feet first, adds a waste allowance for cuts and breakages, and only then converts to boxes. Ten percent waste is standard, but diagonal layouts, herringbone patterns and rooms with many corners and doorways need closer to fifteen. Thin-set and grout are estimated separately and both depend on tile size and trowel notch.
Common uses for Tile Calculator
Buy enough tile for a bathroom floor in one order
Add the right waste allowance for a diagonal layout
Estimate thin-set and grout at the same time as tile
Check a box's stated coverage against the area you measured
Work out how much tile a kitchen backsplash needs
Why tile is always estimated with waste
Every tile job produces cuts. Perimeter tiles are cut to fit, corners and doorways consume pieces, and a percentage break during handling or snap on the wet saw. Ten percent covers those losses comfortably in a simple room. Complex patterns and hard porcelain push the figure higher, and running short mid-job means a second order that may not match the first.
Thin-set and grout are separate line items
Tile is only part of the material cost. Thin-set mortar bonds the tile to the substrate, and its coverage depends on the trowel notch, the tile size and how flat the floor is. Grout fills the joints and is estimated from joint width, tile size and total area. Bags state coverage for specific conditions, and both are cheap next to the cost of running out mid-job.
Order everything at once
Dye lots matter. Tiles in the same model can differ slightly between production runs, and the difference is obvious across a large floor. Order the full area plus waste in a single purchase, check that every box carries the same batch number, and keep the spares. It is also the cheapest moment to add an extra bag of grout and thin-set.
Frequently Asked Questions
How much waste should I add for tile?
Ten percent is the standard allowance for a straight-lay floor or wall in a simple room. Go to 15 percent for diagonal or herringbone patterns, for rooms with lots of corners, jambs and doorways, and for large-format tiles where a single bad cut wastes more area. Keeping one spare box is worth the cost.
How many tiles are in a box?
It depends entirely on the tile. A box of 12 by 12 inch tiles often holds ten, covering 10 sq ft, while large 24 by 24 inch tiles usually come two per box. Mosaic sheets pack far more pieces per box but cover less area. Read the square footage printed on the box rather than counting pieces.
How much thin-set do I need?
A 50 lb bag of thin-set typically covers roughly 60 to 70 sq ft with a quarter-inch notch trowel, which suits most floor tile. Larger tiles need a bigger notch and more adhesive, and back-buttering uses more again. The bag states coverage for its intended trowel size, so check it before you buy.
Should I buy extra tile for repairs later?
Yes. Keep at least one unopened box in case a tile cracks or you need to open a wall for plumbing. Tiles are made in dye lots, and the same model bought two years later can be visibly different. Storing a spare box costs far less than retiling a floor because nothing matches.
Does the calculator work for wall tile?
Yes. Enter the wall area in square feet and the same formula applies. Backsplashes and shower walls often need less waste than floors in a simple rectangular run, but window and niche cutouts raise it. A shower wall area includes the space behind fixtures, so measure the whole surface.