Tile Calculator
Work out exactly how many floor or wall tiles you need, how many boxes to buy, and how much waste to plan for — before you leave the store.
Results
Keep one spare box unopened. If a tile cracks later, matching an old batch is often impossible.
How to Use This Tile Calculator
- Measure the length and width of the area in feet.
- Enter the tile size in inches (for example, 12 × 12 or 12 × 24).
- Choose a waste allowance — 10% for straight layouts, 15% for diagonal.
- Check the box label for tiles per box and enter it.
The calculator converts the tile size to square feet, divides the room area by it, adds waste and rounds up to full tiles and boxes.
Why Tile Waste Matters
Tiles get cut at edges, around doorways and obstacles, and occasionally break during installation. Waste also covers pattern matching (especially with wood-look and marble-look tiles) and future repairs:
- Straight layout: 10% extra is usually enough.
- Diagonal or herringbone: 15% extra.
- Large format (12×24 or bigger): 15–20% extra, because every cut is heavier and more fragile.
Common Tile Sizes and Coverage
| Tile size | Square feet per tile |
|---|---|
| 6 × 6 in | 0.25 sq ft |
| 12 × 12 in | 1.00 sq ft |
| 12 × 24 in | 2.00 sq ft |
| 24 × 24 in | 4.00 sq ft |
Grout lines add a tiny amount of effective spacing, so you will almost always end up with a few spare tiles — exactly what you want.
Frequently Asked Questions
How many 12x12 tiles do I need for a 10x10 room?
A 10×10 room is 100 square feet, and each 12×12 tile covers exactly 1 square foot, so you need 100 tiles plus waste. With the standard 10% allowance, buy about 110 tiles.
How much extra tile should I buy?
Buy 10% extra for straight layouts, 15% for diagonal or herringbone layouts, and up to 20% for large-format tiles or heavy pattern matching.
How many tiles come in a box?
It varies by manufacturer. 12×12 tiles usually come about 10–15 per box (10–15 sq ft per box), while large-format 12×24 tiles come 6–8 per box. Check the label before entering the number.
How many square feet does a 12x12 tile cover?
A 12×12 tile covers exactly 1 square foot. A 12×24 tile covers 2 square feet, and a 6×24 tile covers 1 square foot.