Tile Quantity Calculator
Use this calculator to estimate how many floor or wall tiles you need, including a waste allowance for cuts, breakage, and layout pattern.
How this tile calculator works
This tool answers a common renovation question: how many tiles will I need? It takes your room dimensions, tile size, grout width, and waste allowance, then estimates your total tile count. If you provide tiles-per-box, it also gives you an estimated number of boxes to buy.
The formula is straightforward:
- Convert room size and tile size into a common unit (square meters).
- Calculate room area: length × width.
- Estimate effective tile footprint (tile + grout): (tile length + grout) × (tile width + grout).
- Base tiles = room area ÷ effective tile footprint, rounded up.
- Add waste percentage and round up again.
Why adding waste matters
Almost every tiling job creates offcuts. Even with careful planning, some pieces are lost around corners, doorways, cabinets, drains, and edges. A realistic waste factor helps you avoid running short mid-project.
Typical waste recommendations
- 5%: simple square room, straight lay, experienced installer.
- 10%: most standard home projects.
- 12–15%: diagonal patterns, many cuts, or complex layouts.
- 15%+: herringbone, chevron, or highly irregular spaces.
How to measure your room correctly
1) Split unusual rooms into rectangles
If your room is L-shaped or has alcoves, measure each rectangle separately. Calculate area for each, then add them together.
2) Measure clear tile zones
For floors, you may subtract fixed features (like built-in islands) if they truly won’t be tiled. For walls, subtract large openings such as windows and doors.
3) Use consistent units
This calculator handles unit conversion for you, but accurate inputs still matter. Measure twice and use decimals when needed.
Example calculation
Suppose your bathroom floor is 12 ft × 10 ft, and you chose 24 in × 24 in tiles with 3 mm grout and 10% waste.
- Room area = 120 sq ft (about 11.15 m²)
- Large tiles cover more area per piece, so fewer pieces are needed
- After adding 10% waste and rounding up, you get your purchase quantity
If your supplier sells by box, entering tiles per box converts that number into a practical shopping estimate.
Tips before you buy
- Buy all boxes from the same dye lot whenever possible.
- Check if tile dimensions are nominal or actual.
- Keep a few extra tiles for future repairs.
- Confirm whether trim pieces and edge profiles are sold separately.
- For polished stone or patterned tile, order extra to match veining and orientation.
Frequently asked questions
Should I include grout lines in tile calculations?
Yes, especially for large spaces. Including grout gives a more realistic estimate because each tile occupies slightly more installed footprint than its raw face size.
Can I use this for wall tiles?
Absolutely. Just enter wall width and height as the room dimensions, then subtract big openings manually if needed.
Is this an exact purchase guarantee?
No calculator can replace on-site judgment. Use this estimate as a planning baseline, then confirm with your installer or tile supplier.