Tile Calculator
Calculate how many tiles you need for any floor or wall. Enter room size, tile dimensions, and waste percentage for an accurate count and box order quantity.
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Enter your values above to see the results.
Tips & Notes
- ✓Use 10% waste for straight-lay rectangular patterns and 15% for diagonal (45°) patterns — diagonal cuts waste significantly more tile per row.
- ✓Buy extra tiles from the same production batch for future repairs — dye lots change between runs, and a tile from a different batch may not match your floor even with the same product code.
- ✓For large-format tiles (24"×24" or larger), increase waste to 15-20% — they require more precise cutting and errors are harder to hide.
- ✓Include the grout joint width in your layout planning — 1/8" joints (standard) mean the installed tile covers slightly less than the tile face area per square foot.
- ✓Measure the actual room at its widest and longest points, including alcoves and closets, to avoid running short mid-installation.
Common Mistakes
- ✗Using zero waste — even the most careful installer wastes tile on cuts at walls, around obstacles, and from occasional breaks. Always use at least 10%.
- ✗Entering room dimensions in inches instead of feet, or tile dimensions in feet instead of inches — room goes in feet, tile goes in inches.
- ✗Not rounding up to the nearest full box — tiles are sold in boxes. If you need 8.3 boxes, you must buy 9. Never round down on tile orders.
- ✗Forgetting to subtract large fixed features like islands, bathtubs, or fireplaces from the room area — tiles are only needed for the area actually being tiled.
- ✗Ordering tiles from different boxes without checking lot numbers — tiles from different production lots may have slight color or size variations. Order all tiles at once from the same batch.
Tile Calculator Overview
Accurate tile calculation prevents two equally costly mistakes: ordering too few tiles and having to source more from a different production batch (which may not match), or ordering excessive quantities and wasting money on unusable material. The calculation itself is straightforward; the art is in choosing the right waste percentage for your specific installation.
Tile quantity formula:
Tile Area (sq ft) = (Tile Length × Tile Width) / 144 | Tiles Needed = ⌈Room Area / Tile Area × (1 + Waste/100)⌉
EX: Room 12 ft × 14 ft = 168 sq ft. Tile size 18"×18" → Tile area = (18×18)/144 = 2.25 sq ft per tile. Base tiles = 168/2.25 = 74.7 → round up to 75. With 10% waste: 75 × 1.10 = 82.5 → 83 tiles needed. At 10 tiles/box → 9 boxes (90 tiles) needed.Waste factor guide by pattern type:
| Pattern | Waste Factor | Reason | Best For |
|---|---|---|---|
| Straight lay (horizontal) | 10% | Simple edge cuts only | Most residential floors |
| Offset / brick bond | 10-12% | Half-tile offsets at walls | Modern rectangles, wood-look |
| Diagonal (45°) | 15% | Angled cuts along all walls | Classic, visually enlarging |
| Herringbone | 15-20% | Many short angle cuts | Entry halls, accent areas |
| Chevron | 20% | Precision miter cuts required | Accent walls, feature floors |
| Large format (24"+) | 15% | Cuts harder to salvage | Open plan living areas |
| Tile Size | Tile Area (sq ft) | Tiles to Cover 100 sq ft | Typical Tiles/Box |
|---|---|---|---|
| 4"×4" | 0.111 sq ft | 900 + waste | 45-100 |
| 12"×12" | 1.00 sq ft | 110 (with 10% waste) | 12-15 |
| 18"×18" | 2.25 sq ft | 50 (with 10% waste) | 8-10 |
| 24"×24" | 4.00 sq ft | 29 (with 15% waste) | 4-6 |
| 12"×24" | 2.00 sq ft | 55 (with 10% waste) | 6-8 |
| 3"×12" (subway) | 0.25 sq ft | 440 (with 10% waste) | 40-80 |
Frequently Asked Questions
Divide 100 by the tile face area in square feet, then add your waste percentage. For 12"×12" tiles (1 sq ft each): 100 tiles plus 10% waste = 110 tiles. For 18"×18" tiles (2.25 sq ft each): 100 ÷ 2.25 = 44.4 → round up to 45 tiles plus 10% = 50 tiles. For 24"×24" tiles (4 sq ft each): 100 ÷ 4 = 25 tiles plus 15% waste = 29 tiles. Always round up to the next full tile and then to the next full box.
Standard waste guidelines: 10% for straight-lay rectangular tile in a square room with few obstacles; 15% for diagonal (45°) patterns — every edge tile requires an angled cut; 15% for rooms with many corners, angles, or obstacles; 15-20% for herringbone or chevron patterns; 20%+ for first-time DIY installers who are likely to make more cutting errors; 5-8% for professional installers in simple square rooms. When in doubt, use 15% — the cost of one extra box is far less than the cost of running short and ordering more from a different lot.
Measure each wall area: height × width in feet for each wall. Sum all wall areas. Subtract for the shower/tub opening (if applicable), window openings, and door openings. Apply your waste percentage. Example: bathroom with four walls averaging 5'×8' = 160 sq ft total wall area, minus tub opening 5'×2.5' = 12.5 sq ft → net wall area = 147.5 sq ft. With 15% waste = 169.6 sq ft of tile needed. Divide by tile area per tile to get tile count.
Larger tiles create a more spacious visual effect because fewer grout lines break up the floor plane. A 12"×12" tile in a 100 sq ft bathroom looks more confined than 24"×24" tiles. However, large-format tiles (24"+) require a very flat subfloor — no more than 1/8" variation over a 10-foot span — and are harder to cut. For small bathrooms (under 50 sq ft), 12"×12" or 18"×18" tiles work well. For open-plan living spaces, 24"×24" or 24"×48" large-format tiles create a sleek, expansive look. Smaller mosaic tiles (2"×2", 4"×4") suit shower floors for better grip.
Tile costs vary widely: basic ceramic tile $0.50-3/sq ft; porcelain tile $3-7/sq ft; natural stone $5-20+/sq ft. Labor for professional installation typically adds $4-12/sq ft depending on tile size, pattern complexity, and region. A standard 150 sq ft bathroom floor using mid-range porcelain tile at $5/sq ft with 15% waste (172 sq ft) = $860 in tile. Professional installation at $7/sq ft = $1,050. Total project cost approximately $1,910-2,500 including materials, adhesive, grout, and labor. DIY installation saves the labor cost but requires proper tools including a wet saw, trowels, and spacers.
Diagonal tile patterns use 15% more material than straight-lay because the angled cuts at every wall edge waste more of each tile. Calculate the room area normally, then multiply by 1.15 instead of 1.10. Example: 120 sq ft room, 12"×12" tiles in diagonal pattern → tiles without waste = 120; with 15% waste = 138 tiles. For very angular rooms or rooms with lots of obstacles, increase to 20%. Start the diagonal layout from the center of the room to keep cuts even at all four walls — starting from a corner results in very small, awkward cuts on the opposite walls.