Tile Calculator
Calculate how many tiles you need for a floor, wall, backsplash, or shower. Enter the room dimensions and tile size to get the exact number of tiles required, including waste allowance for cuts and breakage. This tile calculator accounts for grout gap spacing and estimates the number of boxes to purchase.
Related Calculators:
How to Calculate Tiles Needed
- Calculate the total area: length × width
- Calculate single tile area including grout gap
- Divide total area by tile area to get base tile count
- Add 10% waste for straight layouts, 15% for diagonal patterns
- Round up to the nearest whole tile
Tile Size Reference Table
Common tile sizes with coverage per tile and tiles needed per square foot/meter:
| Tile Size (inches) | Size (cm) | Area per Tile (sq ft) | Area per Tile (sq m) | Tiles per sq ft | Tiles per sq m |
|---|---|---|---|---|---|
| 4×4 | 10×10 | 0.111 | 0.010 | 9.0 | 100.0 |
| 6×6 | 15×15 | 0.25 | 0.023 | 4.0 | 44.4 |
| 8×8 | 20×20 | 0.444 | 0.040 | 2.25 | 25.0 |
| 12×12 | 30×30 | 1.0 | 0.093 | 1.0 | 10.8 |
| 12×24 | 30×60 | 2.0 | 0.186 | 0.5 | 5.4 |
| 16×16 | 40×40 | 1.78 | 0.160 | 0.56 | 6.3 |
| 18×18 | 45×45 | 2.25 | 0.203 | 0.44 | 4.9 |
| 24×24 | 60×60 | 4.0 | 0.372 | 0.25 | 2.7 |
| 6×24 | 15×60 | 1.0 | 0.093 | 1.0 | 10.8 |
| 3×6 (subway) | 7.5×15 | 0.125 | 0.011 | 8.0 | 88.9 |
Worked Examples
Example 1: Bathroom Floor (8×10 ft room, 12×24 tiles)
Step 1: Room area = 8 ft × 10 ft = 80 sq ft
Step 2: Tile area = 12" × 24" = 288 sq in = 2 sq ft per tile
Step 3: Base tiles = 80 ÷ 2 = 40 tiles
Step 4: Add 10% waste = 40 × 1.10 = 44 tiles
Result: Order 44 tiles (≈ 4 boxes of 12)
Example 2: Kitchen Backsplash (3×6 subway tiles, 15 sq ft area)
Step 1: Backsplash area = 10 ft wide × 1.5 ft tall = 15 sq ft
Step 2: Each 3×6 subway tile = 0.125 sq ft (8 tiles per sq ft)
Step 3: Base tiles = 15 × 8 = 120 tiles
Step 4: Add 10% waste = 120 × 1.10 = 132 tiles
Result: Order 132 tiles (≈ 11 boxes of 12)
Example 3: Patio (12×16 ft, 18×18 tiles, diagonal layout)
Step 1: Patio area = 12 ft × 16 ft = 192 sq ft
Step 2: Each 18×18 tile = 2.25 sq ft
Step 3: Base tiles = 192 ÷ 2.25 = 85.3 → 86 tiles
Step 4: Add 15% waste (diagonal layout) = 86 × 1.15 = 98.9 → 99 tiles
Result: Order 99 tiles (≈ 9 boxes of 12). Diagonal patterns require more cuts at edges, hence the higher 15% waste factor.
How to Calculate Tiles Needed — Step-by-Step
- Measure the area: Measure the length and width of your room/wall in feet or meters. For irregular shapes, break the area into rectangles and add them together.
- Calculate total square footage: Multiply length × width. For walls, use height × width and subtract window/door openings.
- Determine tile coverage: Calculate the area of one tile in the same units. For inch-sized tiles, convert: (tile length × tile width) ÷ 144 = sq ft per tile.
- Account for grout lines: Add the grout gap width to each tile dimension before calculating tile area. For ⅛" grout on a 12×12 tile: effective size = 12.125" × 12.125".
- Divide area by tile size: Total area ÷ single tile area = base number of tiles needed.
- Add waste factor: Multiply by 1.10 (10%) for straight layouts, 1.15 (15%) for diagonal, or 1.20 (20%) for complex patterns.
- Round up: Always round up to the nearest whole tile and to complete boxes.
Frequently Asked Questions
How much extra tile should I buy for waste?
Add 10% for standard straight layouts, 15% for diagonal or herringbone patterns, and 20% for complex patterns or rooms with many cuts (around obstacles, corners). Always keep a few spare tiles for future repairs.
What is a standard grout gap size?
Standard grout gaps are ⅛ inch (3mm) for wall tiles and 3/16 inch (5mm) for floor tiles. Larger format tiles (24×24) may use ⅛ inch gaps, while natural stone often uses 1/16 inch.
How many 12×12 tiles do I need for 100 sq ft?
For 100 sq ft with 12×12 inch tiles: 100 ÷ 1 = 100 tiles base + 10% waste = 110 tiles. Each 12×12 tile covers exactly 1 square foot.
How do I calculate tiles for a wall?
Measure the wall height × width to get the area. Subtract the area of any windows or doors. Then divide by tile area and add waste percentage, same as floor calculations.
How much extra tile do I need for a diagonal layout?
Diagonal (45-degree) layouts require 15% extra tile compared to 10% for straight layouts. This is because tiles at the room's edges must be cut at angles, producing more unusable offcuts. Herringbone patterns may need 15-20% extra due to the many angled cuts at borders.
Does grout line spacing affect how many tiles I need?
Yes, but the effect is small. Using ¼" grout lines instead of ⅛" on 12×12 tiles reduces the number of tiles by about 2%. For very small tiles like mosaics (1×1 or 2×2), grout lines make a bigger difference — up to 10% fewer tiles needed. This calculator accounts for grout spacing in its calculations.
Can I mix different tile sizes in one room?
Yes, but you need to calculate each tile size separately. Common mixed patterns include a large field tile with a smaller accent border, or versailles/modular patterns using multiple sizes. For modular patterns, manufacturers provide a specific ratio (e.g., 2 large, 1 medium, 1 small per pattern repeat) — order according to that ratio plus waste.
How many tiles come in a box?
It varies by tile size and manufacturer. Common quantities: 12×12 tiles typically come 12-15 per box (~12-15 sq ft). 6×6 tiles come 44-48 per box (~11-12 sq ft). 24×24 tiles come 4-6 per box (~16-24 sq ft). Always check the box coverage (sq ft) listed on the packaging before purchasing.
Tips for Ordering Tiles
Always order 10% extra minimum: This accounts for cuts, breakage during installation, and future repairs. For diagonal patterns, order 15%+ extra.
Check batch/lot numbers: Tiles from different production batches can vary slightly in color and size. Order all tiles from the same batch for consistency. Inspect multiple boxes upon delivery.
Understand return policies: Many tile stores allow returns of unopened boxes within 30-90 days. Order a few extra boxes and return the unused ones — it's much better than running short mid-project.
Keep spare tiles: Store 3-5 spare tiles from your project for future repairs. Tile lines get discontinued, and even the same product can shift in color between production years.
Inspect for quality: Check tiles for warping (lay two face-to-face to check flatness), chipping, and color consistency. Return defective tiles before installation.
Calculate trim pieces separately: Bullnose edges, quarter-round, and listello borders are sold individually or by the linear foot — don't include them in your main tile count.
Consider tile layout direction: Laying rectangular tiles lengthwise along a room makes it appear longer. Crosswise makes it appear wider. Plan your layout before ordering to ensure you have the right quantities for border cuts.
Don't forget grout and adhesive: Estimate 25 lbs of grout per 100 sq ft of 12×12 tiles (more for smaller tiles, less for larger). Thin-set adhesive covers about 60-80 sq ft per 50 lb bag with a ¼" notched trowel.
Buy from a local store if possible: Tile is heavy and expensive to ship. Local purchases also make returns easier. If ordering online, factor in shipping costs per square foot.
Verify tile suitability: Not all tiles work everywhere. Check the PEI rating (wear resistance: 3+ for floors, 1-2 for walls only), slip resistance (COF 0.60+ for wet areas), and frost resistance for outdoor use.