Estimate tiles, boxes, and setting materials for a room from the real row-by-row layout, with grout taken from the joint geometry and no grout quoted for a floating floor.
Change the inputs that matter to your decision. Optional assumptions stay collapsed until you need them.
The material decides which setting products apply. Floating floors take no grout.
77 tiles in 10 boxes covers 140 ft² laid straight (grid).
Counting whole tiles per row and adding the straight (grid) allowance puts the real purchase at 77. The difference is the cut waste an area calculation cannot see.
| Full tiles in the layout | 70Whole units per row × whole rows, so an off-cut is never reused across rows |
|---|---|
| Attic stock | +10%Spares kept back for a future repair |
| Tiles to buy | 7710 boxes of 8 — 3 spare after the job |
| Thin-set mortar | 4 50 lb bagsOne bag covers about 40 ft² at the notch a 24" tile needs |
| Grout | 1 25 lb bagsFrom a 0.1875 in joint around a 12 × 24 in tile |
Setting material coverage follows the notched-trowel sizes in the TCNA Handbook, and grout comes from the joint geometry rather than a flat rate per area. A very flat substrate uses less mortar; a wavy one uses more.
Practical notes about the inputs, assumptions, and result.
Because a tile cut to fill the end of one row cannot also fill the end of the next. The honest count is whole tiles per row multiplied by whole rows, which is what a tiler actually opens. The result shows what a pure area division would have suggested so you can see the difference.
Every unit around the perimeter is cut on an angle and the off-cuts rarely fit anywhere else. This adds about 12% for a 45° diagonal and about 18% for herringbone, on top of the row-by-row count. A straight grid adds nothing beyond the row arithmetic.
Because a floating floor is laid over underlay and has no grout joints. Quoting a grout quantity for it would be inventing a number. Those materials get an underlay quantity instead, and vinyl tile gets adhesive rather than thin-set mortar.
From the geometry of the joints — the joint width, the tile dimensions, and a joint depth proportional to the tile — not from a flat rate per square foot. A 24 inch tile with a 1/8 inch joint has far less joint per square foot than a 6 inch tile with a 1/4 inch joint, and the answer moves accordingly.
It needs a deeper trowel notch to bed properly, so a bag covers less floor. A 50 lb bag covers roughly 95 ft² under a small tile and closer to 40 ft² under a large-format one.
Enough to replace a damaged unit years later, when the run has been discontinued or the shade has moved. The default holds 10% beyond the layout requirement; a box is a reasonable minimum for anything you cannot easily rebuy.
Other tools in construction & diy.
Work out how much paint a room needs from its dimensions, doors, windows, and coat count, then solve for the cheapest combination of tins that actually covers it.
Size a slab, footing, round column, wall, or flight of stairs with thickness in its own unit, then compare bagging the pour against a ready-mix delivery.
Turn a finished concrete volume into cement, sand, gravel, and water for a chosen strength, working back through an explicit dry-volume factor rather than splitting the wet volume.