Enter your room and tile size to get tiles needed, a realistic waste factor, boxes to buy, and an estimated grout line length — plus a real to-scale drawing of your layout for straight, offset (brick) and diagonal patterns. Free, instant, no sign-up.
Defaults to 10%, and auto-switches to 15% for diagonal layouts (extra angled cuts) unless you change it yourself.
Drawn to scale from your actual numbers above — redraws live as you change the room, tile, pattern or starting point.
Measure the room in at least two or three places in each direction — most rooms aren't perfectly square, and walls can bow by half an inch or more over a run. Use the largest rectangle the room forms as your base measurement, then add or subtract features separately: a closet alcove, a peninsula, or a bumped-out cabinet run should be measured and accounted for on its own rather than folded into a single "room size" guess. If the room has fixtures — a tub, a kitchen island, built-in cabinetry — measure the floor area those fixtures actually occupy and subtract it from the total square footage before you calculate tile count, or your material estimate will run high (which is fine for waste, but you'll want to know the real number). Round measurements up to the nearest half-inch rather than down; underestimating room size is the single most common reason installers run short on the last row.
In a straight or offset layout, most of the tiles you cut at the edges are simple rectangular cuts, and many off-cuts can be reused elsewhere in the same row or the next one. A diagonal (45°) layout is different: every tile that touches a wall needs an angled cut, and because the cut is a triangle rather than a rectangle, the leftover piece is far less likely to fit anywhere else in the job. More edge tiles need cutting relative to the field, more of those cuts are wasted material, and pattern-matching on cut tiles (keeping the diagonal grain lined up) burns a few more whole tiles on top of that. That's why this calculator defaults to a 15% waste factor for diagonal layouts instead of the standard 10% — it's a widely used industry rule of thumb, not an exact figure, so treat it as a floor rather than a guarantee on unusually cut-heavy rooms (lots of jogs, angled walls, or a small room where edge tiles are a bigger share of the total).
The grout line length shown in your results is calculated directly from the same grid this tool draws in the canvas preview above — it sums the length of every interior grid line that falls inside your room's dimensions, in whichever pattern you've selected. For diagonal layouts this number is necessarily an approximation: the rotated grid is clipped to the room rectangle, and the exact seam length at the angled edges depends on precisely where each cut falls, which varies with your starting point. Use this figure for sizing grout bags — buying roughly the right amount of grout — not as an exact bill of materials.
Informational planning tool for tile estimating — confirm final quantities and layout with your tile supplier or installer before purchase.