Tile Calculator - How Many Tiles Do I Need?
Miscellaneous
Estimate tile counts and boxes for a floor or wall. Enter room dimensions, tile size, grout gap, and waste percentage to see an instant result.
Rooms / Areas
Results
How to use this tool
- Enter room size. Input the length and width of the room (or click "Add Room" for multiple areas).
- Enter tile size. Enter the tile dimensions and grout gap.
- Set waste & box size. Adjust the waste percentage and enter how many tiles come in a box.
- Read results. See total area, tiles needed, and boxes to buy.
How the tile calculator works
The calculator divides total room area by the effective area of one tile (tile dimensions plus grout gap on each side). It then applies your waste percentage and rounds up to the nearest whole tile and box.
Waste factor
Choose a waste percentage to account for cuts, breakage, and any spare tiles you want to keep for future repairs. Straight layouts often need less extra tile than diagonal or intricate layouts, but the right allowance depends on the project. Enter your chosen percentage in the waste field; the calculator does not select a percentage for you.
Multiple rooms
If you're tiling several rooms or areas with the same tile, add each area using the Add Room button. The calculator sums all room areas and gives a single total tile count.
Grout gap
The grout gap is typically 1.5–3 mm for floor tiles and up to 6 mm for larger format tiles. Check the tile manufacturer's recommendation for the correct joint width.
Tile layout patterns and waste
Use these ranges as planning guidance when choosing a waste percentage. The calculator does not detect or select a layout pattern, so enter the percentage yourself. Actual waste varies with the room shape, tile orientation, cuts around edges and obstacles, and installation conditions.
| Pattern | Waste factor | Notes |
|---|---|---|
| Straight (grid) | 10% | Tiles run parallel to walls; fewest cuts |
| Offset (brick / running bond) | 10–15% | Each row offset by half a tile; more edge cuts |
| Diagonal (45°) | 15–20% | All border tiles require 45° cuts; more waste |
| Herringbone | 15–20% | Complex angles; significant edge cuts |
Thinset, mortar, and grout planning
This calculator estimates tile area, tile counts, and boxes only; it does not calculate how much thinset, mortar, or grout to buy. Coverage depends on the chosen product and installation details. Use the manufacturer's coverage chart for your product, checking the stated application conditions and the factors it specifies, such as trowel size, substrate, tile dimensions, thickness, and grout-joint width. Confirm the estimate against the product label before purchasing.
Tile adhesive types
| Type | Description | Best for |
|---|---|---|
| Type I mastic | Organic adhesive; not water-resistant | Dry interior walls only; not wet areas |
| Type II mastic | Multipurpose; slightly more moisture-resistant | Light-duty damp areas (not shower floors) |
| Modified thin-set | Cement-based with polymer additive | Most general tile applications; floors and wet areas |
| Epoxy mortar | Two-part resin; highest strength and chemical resistance | Commercial kitchens, chemical exposure, heavy traffic |
Frequently asked questions
How do I calculate how many tiles I need?
The calculator divides the total area to be tiled by the grout-inclusive footprint of one tile, then estimates tile counts and boxes using your waste percentage. It does not calculate thinset, mortar, or grout quantities; use the selected manufacturer’s coverage charts for those materials.
What waste percentage should I use?
Choose and enter the percentage yourself; the calculator does not detect or select a layout pattern. As planning guidance, straight layouts often use less waste than diagonal or herringbone layouts, but room shape, cuts, obstacles, and installation conditions affect the amount. Consider keeping extra tiles for future repairs.
How are grout lines accounted for?
The calculator adds the grout gap to both tile dimensions when computing the effective tile footprint. This affects the tile count estimate only; it does not calculate grout quantity. Check the tile manufacturer’s recommendation for joint width and the grout manufacturer’s coverage chart for grout amounts.
Can I calculate tiles for multiple rooms?
Yes. Use the "Add Room" button to add additional rooms. All room areas are summed before calculating tile quantities.