Tile Calculator
Tiles and boxes, with the waste the pattern actually needs.
Work out Tile. Tiles and boxes, with the waste the pattern actually needs. Shows the volume in every unit a yard might quote in.
10% straight lay; 15–20% for diagonal or patterned.
Leave at zero to skip the box count.
Tiles needed
220
12″ × 12″ · 1.000 sq ft each
The waste allowance is what decides whether you finish the job. 10% suits a straight lay in a simple room; a diagonal or herringbone, or a room with many obstacles, needs fifteen to twenty. And buy a few beyond that from the same batch — tiles from a different production run can differ visibly in shade.
How the Tile Calculator works
Tile count is area divided by tile area, with waste added — and the waste allowance is the part that decides whether you finish the job. Ten percent covers a straightforward square-laid floor. A diagonal layout, a herringbone, or a room with many cuts can need twenty percent or more, and a mid-job reorder risks a different batch with a visibly different shade.
Also known as: how many tiles do I need · floor tile calculator · tile waste calculator · tile calculator square feet
The calculation itself
Area times one plus the waste fraction, divided by the area of one tile. Tile dimensions are in inches and the area in square feet, so the conversion is 144 square inches to the square foot — a 12-inch tile is exactly one square foot.
In practice
200 square feet with 10% waste is 220 square feet. At one square foot a tile, that is 220 tiles.
Halve the tile to 6 inches and its area quarters, so the same floor needs four times as many — 880. Tile count is quadratic in the tile dimension, which is why a small change in tile size changes the order so much.
The waste allowance is what decides whether you finish. Ten percent suits a straight lay in a simple room. A diagonal or herringbone, or a room with many obstacles, needs fifteen to twenty, because each cut leaves an offcut that fits nowhere else.
Why to buy beyond the waste
Batch shading. Tiles from a different production run can differ visibly in colour, and a mid-job reorder is exactly when you will get one.
Spares also cover future repairs. A cracked tile five years on is a trivial fix with a matching tile and a visible patch without one.
Large-format tiles waste more per cut because each offcut is bigger, so the usual ten percent understates a big tile in a small awkward room.
Acting on it
Set the waste from the pattern, not from habit. Straight lay and herringbone are different jobs.
Buy full boxes from one batch and keep the spares. The box count matters more than the tile count at the till.
Dry-lay a row before fixing anything, to see where the cuts land. Moving the starting line can remove a whole row of awkward cuts.
Frequently asked questions
How many tiles do I need?
Area in square feet, times one plus the waste fraction, divided by the tile's area. A 12-inch tile is exactly one square foot, so 200 square feet at 10% waste is 220 tiles.
How much waste should I allow?
Ten percent for a straight lay in a simple room. Fifteen to twenty for a diagonal or a pattern, and more again for a room with lots of obstacles — each one produces cuts you cannot reuse.
Why should I buy extra beyond the waste?
Batch shading. Tiles from a different production run can differ noticeably in colour, so a few spares from the original batch are worth keeping for future repairs as well as for the job itself.
Does tile size change how much waste I need?
Yes. Large-format tiles waste more per cut because each offcut is bigger, so a big tile in a small awkward room can waste far more than the usual ten percent.
How do I calculate for a wall rather than a floor?
Identically — it is still area divided by tile area. Wall layouts often need more waste because they are more visible, so the cuts get placed more carefully and the offcuts suit fewer positions.
Put this calculator on your own site
Free to use, on any site, commercial or not. Paste this where you want it to appear. It is a plain iframe, so it works in WordPress, Squarespace, Wix, Webflow, Ghost and anything else that accepts HTML.
<iframe src="https://www.thecalclibrary.com/embed/tile-calculator" width="100%" height="640" style="border:1px solid #e2e8f0;border-radius:12px" loading="lazy" title="Tile Calculator"></iframe>The only condition is that the credit line stays visible. It sits inside the frame, so you do not have to do anything to keep it.