Home & Garden
Tile Calculator
Enter room and tile sizes, waste allowance, and box info to estimate floor area, tiles with waste, boxes to buy, and cost. Handles inches and centimetres, feet and metres. An estimate — cuts and breakage vary by layout.
Last updated: September 30, 2026
Your result · Boxes to buy
14
Rounded up, waste included.
- Floor area
- 120sq ft
- Tiles with waste
- 132
- Estimated cost
- $350.00
- Tiles, no waste
- 120
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What your result means
Boxes to buy is the headline: whole boxes covering tiles plus waste. Tiles with waste shows the underlying count the boxes satisfy.
Floor area is the measured room; compare it against the box coverage printed on the packaging as a sanity check.
How the calculation works
- Multiply room dimensions for floor area, converting tile size to the same base.
- Divide floor area by one tile’s area, then add the waste percentage.
- Divide by tiles per box (or coverage per box), rounding up to whole boxes.
Formula
Formula
tiles = room area ÷ tile area; with waste × (1 + waste); boxes = round up ÷ per box (or ÷ coverage)
- Floor arearoom length × room width
- Tilesfloor area ÷ single tile area (units converted)
- With wastetiles × (1 + waste %)
- Boxesround up (tiles ÷ per box) or (area ÷ coverage per box)
Worked examples
Example: 10×12 ft room, 12-inch tiles, 10/box at $25
- roomUnit: ftroomLength: 10roomWidth: 12tileUnit: intileLength: 12tileWidth: 12wastePct: 10tilesPerBox: 10pricePerBox: 25
Result: Floor area 120 · Tiles, no waste 120 · Tiles with waste 132 · Boxes to buy 14 · Estimated cost $350.00
Example: same room by box coverage (20 sq ft/box)
- roomUnit: ftroomLength: 10roomWidth: 12tileUnit: intileLength: 12tileWidth: 12wastePct: 10coveragePerBox: 20pricePerBox: 25
Result: Floor area 120 · Tiles, no waste 120 · Tiles with waste 132 · Boxes to buy 6 · Estimated cost $150.00
Assumptions
What this calculation takes for granted — check these before relying on the result.
Assumptions:
Limitations
Why your real figure may differ:
Frequently asked questions
How much waste should I add for tiles?
10% for straight lays in square rooms, 15% for diagonals or many cuts, 20% for intricate patterns. Complex rooms beat any rule — add a spare box.
Tiles per box or coverage per box?
Use tiles per box when printed on the box — it is exact. Coverage per box is a rounded marketing figure; it works but can undercount slightly.
Do grout joints change the count?
Slightly downward: joints consume area tiles would cover. The effect is small next to waste, so this calculator ignores joints conservatively.
Why buy whole boxes?
Stores sell sealed boxes and dye lots vary between batches. Buying whole boxes from one lot keeps colour consistent and covers breakage.