Tile Calculator
Enter the dimensions of the area you're tiling and your tile size to find out exactly how many tiles — and how many boxes — you'll need to buy, including an adjustable waste allowance.
Project Dimensions
Results
Total Area
Tiles (no waste)
Tiles with Waste
Boxes to Buy
How to Calculate How Many Tiles You Need
The process has three steps:
- Calculate total square footage (or square meters) — Measure the length and width of the room and multiply. For rooms with odd shapes, break them into rectangles and add the areas together. The "+ Add another area" button above handles this automatically.
- Calculate individual tile area — Multiply the tile's width by its height. Convert to the same unit as your room if necessary.
- Divide and apply waste factor — Divide room area by tile area to get the raw tile count. Multiply by (1 + waste %) to account for cuts and breakage.
Choosing the Right Waste Factor
| Waste % | When to Use |
|---|---|
| 5% | Simple rectangular room, straight (non-angled) tile lay |
| 10% | Standard rooms with only a few cuts, most tile projects |
| 15% | Diagonal (45°) layout, L-shaped rooms, natural stone with imperfections |
| 20%+ | Herringbone, basket-weave, or other complex patterns |
Always buy at least 10% extra and keep a few tiles in storage. If a tile cracks years later, matching an out-of-production tile is difficult or impossible.
Estimating Grout and Adhesive
Tile is just one material cost. A 50 lb bag of floor adhesive (thinset mortar) covers roughly 40–50 square feet. Grout coverage varies by tile size and joint width — smaller joints use less grout. Check the packaging for manufacturer coverage estimates. Your flooring calculator can also help if you're comparing tile costs against other flooring options.
For walls and backsplashes, the same formula applies — just measure the wall area (length × height), subtract any windows or large openings, and use a 10–15% waste factor for the extra cuts around outlets and edges.
Frequently Asked Questions
Do I need to subtract the area of cabinets or islands?
Yes — only tile the floor area that is actually exposed. For kitchen floors, you typically tile under appliances (in case they're moved) but can skip under built-in cabinets. When in doubt, tile the full footprint and keep extras for future repairs.
How many tiles fit in a box?
Box sizes vary by manufacturer and tile size. Small mosaic tiles might come 10–12 per sheet, while large-format 24×24 tiles might come 2–4 per box. Always check the label for exact tile count and coverage area per box.
Can I use this for wall tile?
Yes. Enter the wall length and height as your "room" dimensions. Subtract any windows or large openings (add them as negative areas, or just recalculate with a smaller total). Use a 10% waste factor since wall cuts around outlets and edges add up quickly.
What is "rectified" tile?
Rectified tiles are machine-cut to precise dimensions, allowing very narrow grout joints (as thin as 1/16"). Non-rectified tiles have slight natural size variations and require wider joints. Rectified tile can give a sleeker look but costs more.
