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Whether you're tiling a bathroom floor, kitchen backsplash, shower enclosure, or entire room — this guide walks you through exactly how much tile to buy. You'll learn the universal formula, see waste factors for every layout pattern, and get quick-reference tables for common room sizes.
Tiles Needed = (Room Area ÷ Tile Area) × (1 + Waste Factor)
Measure your space in square feet, divide by the area of one tile, then add 10–20% for waste depending on your layout pattern.
Every tile quantity calculation uses the same core formula, regardless of whether you're tiling a floor, wall, or backsplash:
Area of Space (sq ft) ÷ Area of One Tile (sq ft) = Base Tiles
Base Tiles × (1 + Waste Factor) = Total Tiles Needed
For example, a 10×12-foot room (120 sq ft) using 12×12-inch tiles (1 sq ft each) needs 120 base tiles. With a 10% waste factor for a straight layout: 120 × 1.10 = 132 tiles.
Always convert tile dimensions to the same unit as your room measurements. A 12×24-inch tile = 1×2 feet = 2 sq ft per tile. A 6×6-inch tile = 0.5×0.5 feet = 0.25 sq ft per tile.
Floors are the most common tiling surface. Here's how to measure and calculate:
Measure the length and width of the room in feet. For L-shaped or irregular rooms, break the space into rectangles, calculate each one separately, and add them together.
Subtract permanent fixtures like vanity cabinets, islands, or built-in shelving. Don't subtract toilets or freestanding furniture — tile under them for flexibility.
Add 10% for straight layouts or 15–25% for complex patterns. This covers cuts at edges, breakage, and future repairs.
Example: A 10×12 bathroom = 120 sq ft. With a vanity (2×4 ft = 8 sq ft) subtracted: 112 sq ft. Using 12×24-inch tiles (2 sq ft each) with 10% waste: (112 ÷ 2) × 1.10 = 62 tiles.
Wall tile calculations use height instead of a second floor dimension. Measure each wall separately for the most accurate count:
Add together all the walls you plan to tile, then subtract windows, doors, and any areas you won't be covering.
A standard window is roughly 10–15 sq ft. A standard door opening is about 21 sq ft (3×7 ft). Subtract these from your total wall area before adding waste.
Walls with windows, electrical outlets, and niches typically need 10–15% waste. Simple accent walls with no cutouts may only need 5–10%.
Example: An accent wall measuring 12 ft wide × 9 ft tall = 108 sq ft. Using 4×12-inch subway tiles (0.33 sq ft each) with 10% waste: (108 ÷ 0.33) × 1.10 = 360 tiles.
Backsplashes are smaller areas but often involve more cutouts around outlets, switches, and windows. The standard height from countertop to upper cabinets is about 18 inches (1.5 ft).
Behind the stove, the backsplash often extends up to the range hood — typically 30–36 inches high instead of 18. Calculate this section separately and add it to your total.
Add 10–15% waste. The smaller area means fewer tiles overall, but outlets and corners increase cutting waste proportionally.
Example: A 10-foot counter with an 18-inch backsplash = 15 sq ft. Range area adds 3 ft × 3 ft = 9 sq ft. Total: 24 sq ft. With 15% waste: 24 × 1.15 = 28 sq ft of tile needed.
Showers require tile on multiple walls and the floor. Measure each surface separately:
Measure each wall (width × height) individually. A standard 3×3-ft shower with 8-ft ceilings has three walls of 3×8 = 24 sq ft each, totaling 72 sq ft. If you tile to ceiling, the back wall and two side walls are all included.
Shower floors are often 3×3 ft (9 sq ft) or 3×5 ft (15 sq ft). Small mosaic tiles are common for shower floors and may need 15% waste due to more grout lines and cuts around the drain.
Don't forget shower niches (typically 12×24 inches interior = ~4 sq ft with all sides) and corner benches (~6–8 sq ft of tile). These small areas still need their own calculations.
Example: 3×3-ft shower, 8-ft ceilings: 3 walls × (3 × 8) = 72 sq ft walls + 9 sq ft floor + 4 sq ft niche = 85 sq ft. With 15% waste: 85 × 1.15 = 98 sq ft of tile needed.
The layout pattern you choose directly affects how much extra tile you need. Patterns with angled or staggered cuts produce more waste than simple grid layouts:
| Layout Pattern | Waste % | Why |
|---|---|---|
| Straight / Grid | 5–10% | Minimal cuts — only at room edges |
| Brick / Running Bond | 10–15% | Staggered rows require half-cuts at each end |
| 1/3 Offset Stagger | 10–15% | Similar to brick but with 1/3 offsets |
| Diagonal / 45° | 15–20% | Every edge tile is cut at an angle |
| Herringbone | 15–25% | Many angled perimeter cuts and V-shaped ends |
| Chevron | 15–25% | Pre-cut angles still waste material at borders |
| Versailles / Modular | 20–25% | Multiple tile sizes; complex fit at edges |
Most online calculators only give you a flat percentage. Our tile calculator generates actual cut lists based on your chosen pattern — so you see exactly which tiles get cut and how much material is really wasted.
Use this table for a rough estimate of how many 12×12-inch tiles you need for common room sizes (including 10% waste for a straight layout):
| Room Size | Square Feet | 12×12" Tiles (with 10% waste) | Boxes (10 tiles/box) |
|---|---|---|---|
| 5×5 ft | 25 sq ft | 28 | 3 |
| 6×8 ft | 48 sq ft | 53 | 6 |
| 8×10 ft | 80 sq ft | 88 | 9 |
| 10×10 ft | 100 sq ft | 110 | 11 |
| 10×12 ft | 120 sq ft | 132 | 14 |
| 12×12 ft | 144 sq ft | 159 | 16 |
| 12×16 ft | 192 sq ft | 212 | 22 |
| 15×20 ft | 300 sq ft | 330 | 33 |
This table uses 12×12-inch tiles. For other sizes, divide your room's square footage by the tile area in square feet. For example, with 6×6-inch tiles (0.25 sq ft each), a 100 sq ft room needs 400 base tiles + waste. Use our calculator for any tile size and pattern.
Enter your room dimensions, choose your tile size and pattern, and get an exact tile count with visual layout preview. Our calculator handles waste factors, cut lists, and pattern alignment automatically.
Written by the TilePro Calculator Team
Professional tile layout tools and guides since 2026