Tile Estimator
Enter your floor dimensions and tile size to find out how many tiles to order — with the right waste allowance so you never run short mid-project.
Runs entirely in your browser — your numbers never leave this page.
How it works
Tile estimating is area division plus a waste allowance for cuts:
Tiles = ceil(Floor sq ft ÷ Tile sq ft × (1 + Waste))
- Example: a 10 × 12 ft floor (120 sq ft) with 12 × 12 in tiles (1 sq ft each) at 10% waste → 120 × 1.10 = 132 tiles.
- 10% waste covers a straight grid layout in a simple room. 15% covers diagonal layouts or rooms full of cuts (hallways, L-shapes, many doorways).
- Measure the full rectangle — do not subtract the toilet or vanity footprint; those cutouts are exactly what the waste allowance is for.
- Boxes: divide floor sq ft by the coverage printed on the box and round up to whole boxes. Keep one spare box for future repairs.
Frequently asked questions
How do I measure around toilets and vanities?
Do not subtract them — measure the full rectangle of the room. The tiles cut to fit around fixtures come out of your waste allowance, which is exactly what it is for.
Why does a diagonal layout need more waste?
Every tile meeting a wall on a diagonal needs two angled cuts, and the triangular offcuts are unusable. That pushes waste from ~10% to ~15% (20% for complex rooms).
Do grout lines change how many tiles I need?
Barely. Standard 1/8–3/16 in joints add a tiny bit of coverage per tile, but the effect is well under 1% — your waste allowance swallows it completely.
What is lippage, and why do large tiles need a flat floor?
Lippage is when one tile edge sits higher than its neighbor — a toe-stubber. Large-format tiles magnify any unevenness in the subfloor, so the floor must be flat (often within 1/8 in over 10 ft) and installers use leveling clips.
What underlayment goes under floor tile?
Tile needs a rigid, dimensionally stable base: cement backer board in wet areas, or an uncoupling membrane (like Ditra) over plywood. Never tile directly over plain plywood subfloor — flex cracks grout and tile.
Why does everyone say to buy the same dye lot?
Tile shade varies slightly between production batches. Boxes from different dye lots can look like different colors once laid side by side. Check the lot number on every box before you leave the store.
How many boxes do I need?
Divide your floor square footage (with waste) by the coverage printed on the box, then round up to whole boxes. Example: 132 sq ft ÷ 15 sq ft/box = 8.8 → buy 9 boxes.
How should I lay wood-look plank tile?
Use a 1/3 offset (staggered), not a 50% brick pattern. Long planks often have a slight bow, and a half-offset lines the bow up into visible lippage. A third-offset keeps it flat.
Can I tile directly over existing tile?
Sometimes — if the old tile is sound, level, and well-bonded. You gain height at doorways and transitions, so check clearances. Loose, cracked, or uneven old tile must come up first.
Should I seal the grout?
Yes for cement-based grout in wet or high-traffic areas — sealer buys you stain resistance and easier cleaning. Epoxy grout does not need sealing but is harder to install. Re-seal cement grout every 1–2 years in showers.