Formula used
- Room Area = Length × Width (converted to square meters)
- Net Area = Sum(Room Areas) − Cutouts (if subtracting)
- Area With Waste = Net Area × (1 + Waste%/100)
- Tile Area = Tile Length × Tile Width (optionally + grout gap)
- Tiles Needed = ceil(Area With Waste ÷ Tile Area)
- Boxes Needed = ceil(Tiles Needed ÷ Pieces Per Box) or ceil(Area With Waste ÷ Coverage Per Box)
- Total Boxes = Boxes Needed + Spare Boxes
How to use this calculator
- Choose a mode based on your box label: pieces per box or coverage per box.
- Enter one or more room dimensions for your surface area.
- Add exclusions like planters or drains if you want them subtracted.
- Enter tile size and pick whether grout gap affects coverage.
- Select your pattern and set waste for cuts and breakage.
- Submit to see boxes, tiles, and export options instantly.
Example data table
| Project | Area (ft²) | Tile Size | Waste | Mode | Box Label | Estimated Boxes |
|---|---|---|---|---|---|---|
| Garden patio | 120 | 12×12 in | 12% | Pieces/box | 10 tiles/box | 14 |
| Outdoor steps | 45 | 6×24 in | 18% | Coverage/box | 9.5 ft²/box | 6 |
| Path border | 70 | 8×8 in | 10% | Pieces/box | 20 tiles/box | 6 |
Tip: For natural stone and handmade tiles, increase waste for variation and breakage.
Why box-based estimating reduces project surprises
Tile projects in garden spaces often fail at the supply stage, not the install stage. Boxes contain a fixed mix of pieces, shade runs, and calibrated coverage, so estimating in boxes improves purchasing accuracy and color consistency. This calculator converts your measured area into a rounded box count, then adds controlled waste for cuts, breakage, and edge trimming. It also supports exclusions for drains, planters, posts, and fixed features so your order reflects the real surface to be covered.
Area inputs that match outdoor layouts
Outdoor surfaces rarely behave like perfect rectangles. Use multiple rooms to model patios, side yards, and stepping-stone sections as separate rectangles, then combine them automatically. For curved paths, measure several widths and enter an average to avoid underbuying. If you need to tile around permanent features, subtract cutouts by count and typical area to keep the net area realistic.
Waste planning for patterns and hard edges
Waste is not a guess; it is a risk allowance. Straight layouts typically need 8–12% waste, while diagonal and herringbone layouts require more offcuts, especially near borders and garden edging. Outdoor projects also face higher breakage risk due to handling, uneven substrates, and thicker porcelain or stone. The pattern uplift option helps standardize that extra buffer, but you can override it when your layout is simple or highly modular.
Tile size, grout gaps, and coverage behavior
The tile face size drives tile count, while grout gaps influence module size in tight grid installations. When you include grout gap, the calculator treats each tile as occupying slightly more space, which can reduce the tile count marginally. This is useful for uniform spacers and consistent joints, but for irregular stone edges, keep the estimate based on the tile face and let waste cover the variability.
Choosing the best box label mode
Some boxes specify pieces per box, while others list coverage per box. Pieces-per-box is strongest when all tiles are identical and the face size is reliable. Coverage-per-box is best when the manufacturer has already accounted for tile dimensions and packaging. After you submit, download CSV for ordering sheets and PDF for site records, then add one spare box for future repairs and matching.
FAQs
1) What waste percentage should I use for a garden patio?
For straight layouts on a rectangular patio, start at 10%. Increase to 15% if the perimeter has many cuts, steps, or curved borders. Use higher values for stone or handmade tiles to cover breakage and sorting.
2) Should I subtract cutouts like drains or planters?
Subtract cutouts when the feature is permanent and won’t be tiled. Keep cutouts included when you will tile over the area or when the shape is complex and waste already covers the difference.
3) Why does diagonal or herringbone need more boxes?
These patterns create more triangular offcuts and shorter usable remnants. Borders and corners amplify losses, so the same net area requires more tiles. The built-in uplift helps prevent underbuying for patterned layouts.
4) When should I use “coverage per box” mode?
Use it when your box label lists coverage such as ft² or m². Manufacturer coverage often reflects packaging realities and can be more reliable than counting pieces, especially for mixed-size sets or mesh-mounted sheets.
5) Does including grout gap make the estimate more accurate?
It can for consistent grid spacing, because each tile “module” occupies tile plus joint. For variable stone edges or non-uniform joints, exclude grout gap and rely on waste to absorb layout differences.
6) How many spare boxes should I keep after installation?
Keep at least one spare box for outdoor work where chips and repairs happen. For large or high-traffic areas, consider two spares. Store boxes dry and shaded to preserve color and surface finish.