CalculatorEnter your measurements below and it works the answer out.
Area divided by coverage, plus 10% waste, rounded up to whole tiles. Enter what you measured and pick how it is sold.
The arithmetic. Work out the area, divide by what one tile covers, add 10% waste, round up. Nothing more than that — the value of the page is the coverage figures and the waste allowance, both of which are stated here rather than hidden inside the tool.
Why the waste allowance is 10%. Ten per cent extra is the allowance for a floor laid square to the walls. Go to fifteen for a diagonal or herringbone layout, and keep a full box back — tile is made in batches and a replacement in two years will not match.
How it is sold. Tile is sold by the box and priced by the square foot. Box coverage differs by product, so this gives you tiles and square feet and leaves the box count to the label in front of you.
Measure the openings honestly. Deduct large openings — a garage door, a picture window, a stairwell — and ignore small ones. Cutting a sheet or a board around a normal door wastes more material than the opening saves, which is why trades quote gross area and let the waste allowance absorb it.
Round up to how it is sold. A calculator that tells you 6.3 sheets is not finished. Everything below is rounded up to whole units, because that is what you can actually buy.
Divide your area in square feet by the coverage of one tile, then add 10% and round up. At 1 sq ft each, a 200 sq ft job needs 221.
10% is what this calculator adds. Ten per cent extra is the allowance for a floor laid square to the walls. Go to fifteen for a diagonal or herringbone layout, and keep a full box back — tile is made in batches and a replacement in two years will not match.
Ten per cent for a straight layout, fifteen for diagonal or herringbone, and a spare box on top for future repairs. Dye lots change between production runs, so a box bought later rarely matches.