Tile Square Footage Calculator
Calculate square footage, tile count, and boxes needed for any floor or wall tile project — straight or diagonal layouts.
Last updated:Tip: If you only have the diameter, divide by 2 to get the radius.
L-shape = two rectangles sharing a corner.
Add one row per rectangle and we'll sum them.
How to Calculate Tile Square Footage
- Measure the surface — floor, wall, or backsplash — using length × width.
- Add a waste factor per the table below.
- Calculate tile count: total area ÷ area of one tile.
- Round up to full boxes. Tiles per box varies by size.
Tile Waste Factor by Layout
Waste allowances follow Tile Council of North America (TCNA) guidance.
| Layout | Recommended Waste | Notes |
|---|---|---|
| Straight / stacked | 10% | Standard for 12" and 18" tiles. |
| Diagonal | 15% | More cuts at the edges. |
| Herringbone | 15% | Extra for pattern matching. |
| Large format (24"+) | 20% | Any cut wastes a lot of material. |
| Subway pattern (brick) | 12% | End cuts on every other row. |
Tiles Per Square Foot (Common Sizes)
| Tile Size | Area (sq ft each) | Tiles per 100 sq ft |
|---|---|---|
| 4 × 4 in | 0.111 | 900 |
| 6 × 6 in | 0.25 | 400 |
| 8 × 8 in | 0.444 | 225 |
| 12 × 12 in | 1.0 | 100 |
| 12 × 24 in | 2.0 | 50 |
| 18 × 18 in | 2.25 | 45 |
| 24 × 24 in | 4.0 | 25 |
Example: 8 × 10 Bathroom Floor
- Area: 8 × 10 = 80 sq ft
- Waste (straight pattern, 12×12 tile): 10% → order for 88 sq ft
- Tiles needed (12×12): 88 tiles
- Boxes (if 10 tiles/box): ceil(88 / 10) = 9 boxes
Walls & Backsplashes
For tile walls and backsplashes, measure each wall section separately and add them. Subtract window and door openings larger than 10 sq ft. For a 10 ft × 4 ft backsplash, area is 40 sq ft — add 10% for 44 sq ft. A standard backsplash is 18 inches tall from counter to underside of wall cabinets.
Grout, Thinset, and Sealer Estimates
| Material | Coverage | Notes |
|---|---|---|
| Sanded grout | ~0.5 lb / sq ft (12×12 tile, 1/4" joints) | Use for joints ≥ 1/8 in. |
| Unsanded grout | ~0.3 lb / sq ft (small tile, 1/16" joints) | Use for glass and polished marble. |
| Modified thinset | ~35 sq ft per 50 lb bag (3/8" notched trowel) | Backbutter large-format tile. |
| Sealer (natural stone) | ~250 sq ft per quart | Re-apply every 1–2 years. |
Common Tile Layout Patterns
- Straight / stacked: simplest, 10% waste. Works with any rectangular tile.
- Running bond (subway): 12% waste. Offset each row by half a tile.
- Diagonal: 15% waste. Rotate tile 45°; more cuts at walls and niches.
- Herringbone: 15–20% waste. Each row needs two 45° cuts at the ends.
- Basketweave: 12% waste. Pairs of tiles alternate direction — buy by the pair.
Example: 10 × 12 Kitchen Floor (12×24 Tile, Diagonal)
- Area: 10 × 12 = 120 sq ft
- Diagonal layout waste: 15% → 138 sq ft
- Tiles needed: 138 ÷ 2 = 69 tiles
- Boxes (6 tiles/box): ceil(69 / 6) = 12 boxes
- Thinset: 138 ÷ 35 = 4 bags (50 lb)
- Grout: 138 × 0.5 = 69 lb → 2 × 25 lb bags
Frequently Asked Questions
How many 12x12 tiles are in 100 sq ft?
Exactly 100 tiles. Each 12 × 12 inch tile covers 1 sq ft. With a 10% waste factor you will actually order 110 tiles.
How much waste should I add for tile?
10% for straight-lay, 12% for subway (running bond), 15% for diagonal or herringbone, and 20% for large-format 24-inch tile or complex patterns.
How many tiles do I need for a 10x10 floor?
100 sq ft, about 110 sq ft with 10% waste. That is 110 tiles of 12×12, 50 tiles of 12×24, or 28 tiles of 18×18.
Do I need extra tile for future repairs?
Yes — keep at least one full box on top of your waste factor, stored in the original packaging. Tile runs and dye lots are discontinued frequently.
How much grout do I need per square foot?
Roughly 0.5 lb per sq ft for 12×12 tile with 1/4 in grout lines. Large-format 24" tile needs about half that. Mosaic sheets need closer to 1 lb per sq ft.
Should I buy tile in boxes or by the piece?
Always buy by the full box. Retailers rarely let you mix boxes and shade variation between boxes is normal — order all boxes from the same production run.
How do I calculate backsplash tile?
Multiply backsplash length × height (usually 18 in from counter to cabinet). Subtract about 0.2 sq ft per outlet. A 10 ft × 18 in backsplash is 15 sq ft; round up to 17 sq ft with waste.
Do I need thinset mortar along with the tile?
Yes. Budget about 1 bag (50 lb) of modified thinset per 35 sq ft of tile for 3/8" notched trowel applications. Large-format tile needs a bigger trowel and more thinset.