How Much Tile Do I Need? (Step by Step With Waste Factor)
Ordering the right amount of tile starts with three steps: measuring your space, calculating total area, and adding a safety margin. This guide walks you through each one, with a worked example to show the complete process.
Step 1: Measure Your Room
Measure the length and width of each area you plan to tile. Use a tape measure and round to the nearest half-foot. If your space is an unusual shape, break it into rectangles:
- Measure each rectangle separately
- Calculate area for each (length × width)
- Add all areas together for the total
Worked Example: Bathroom Remodel
Floor: 8 ft (length) × 6 ft (width) = 48 sq ft
Wall (shower surround): 5 ft (height) × 3 ft (width) = 15 sq ft
Total area to tile: 48 + 15 = 63 sq ft
Step 2: Know Your Tile Coverage
Every tile box displays coverage — the number of square feet that one box covers. Find this on the product label or in the online product listing. For example:
- A 12×12 tile (1 sq ft per tile) in a box of 10 = 10 sq ft coverage
- An 18×18 tile (2.25 sq ft per tile) in a box of 4 = 9 sq ft coverage
- A 6×12 tile (0.5 sq ft per tile) in a box of 40 = 20 sq ft coverage
Always use the box coverage, not the individual tile size, because boxes contain different quantities.
Step 3: Add Your Waste Factor
Waste accounts for cuts, breakage, and layout adjustments. Standard waste factors are:
| Layout Pattern | Waste % |
|---|---|
| Straight grid (no cuts, rectangular room) | 10% |
| Straight grid with standard wall cuts | 12–15% |
| Staggered or offset pattern | 15% |
| Diagonal pattern | 15–20% |
| Complex layout with many cuts or mosaics | 20%+ |
Formula: Total area with waste = Room area × (1 + waste % / 100)
Step 4: Calculate Boxes to Order
Divide your total area (including waste) by the box coverage, then round up to the next whole number. You cannot order a partial box.
Continuing the Example
Room area: 63 sq ft
Waste factor: 15% (staggered floor, standard wall cuts)
Area with waste: 63 × 1.15 = 72.45 sq ft
Tile box coverage: 10 sq ft per box
Boxes needed: 72.45 ÷ 10 = 7.245 → order 8 boxes
Total tile: 8 × 10 = 80 sq ft
Pro Tips
- Keep a reserve: After installation, set aside a few spare tiles from your order in a cool, dry place. Future repairs or replacements need matching tile, and dye lots change.
- Ask your supplier: If you are unsure about waste for your specific pattern or tile size, your supplier or installer can refine the estimate based on their experience.
- Verify before you buy: Double-check the box coverage on the product label — designs can vary, and an online listing may not match the actual box in the store.
- Account for grout lines: If your tile is large (16×16 or bigger), grout lines are wider and use a little more material. The 10–20% waste range already accounts for this, but confirm with your installer.
Use the Tile Calculator
If you prefer not to calculate by hand, our Tile Calculator will do the math for you. Simply enter your room dimensions, waste percentage, and tile box coverage — it instantly shows you how many boxes to buy.
Related Guides
Frequently Asked Questions
For straight grid layouts, add 10%. For straight grids with standard wall cuts, add 12–15%. For staggered patterns, add 15%. For diagonal layouts, add 15–20%. Always round up to the nearest full box. Using our calculator handles this automatically.
The coverage is printed on every tile box in square feet (or square meters). Look for "Coverage" or "Covers" — this tells you how many sq ft one box provides. If you cannot find it, divide the box dimensions by the individual tile size to estimate coverage.
Include closets if they will be tiled. For areas under cabinets and sinks, measure only if you plan to replace them later and need tile behind them. If those areas are permanent, skip them.
Break the space into two or more rectangles. Measure each rectangle separately (length × width), add all areas together, then apply the waste factor to the total.
Most tile retailers accept returns within 30 days, but always verify the store's return policy first. Keep your receipt and original packaging. Slightly over-ordering is better than running short mid-project.
Set aside 2–5% of the total ordered amount for future repairs and touch-ups. Store it in a cool, dry place in its original box. This spare tile is invaluable if you need to patch damage later.