Updated October 2026
Australian tile retailers sell by the box with coverage quoted in square meters, and standard tile sizes are metric — a slightly different buying convention from the US imperial-box norm, but the same underlying calculator math applies cleanly once converted.
| AU size | Enter as (inches) | Typical use |
|---|---|---|
| 300mm × 300mm | 11.81" × 11.81" | Bathroom floors |
| 300mm × 600mm | 11.81" × 23.62" | Bathroom walls |
| 600mm × 600mm | 23.62" × 23.62" | Living areas, kitchens |
| 600mm × 1200mm | 23.62" × 47.24" | Large-format living/outdoor |
A 2.4m × 1.8m bathroom floor (4.32 m²) in 300mm × 300mm tile with a 3mm joint: enter room length 7.87 ft, room width 5.91 ft, tile 11.81" × 11.81", grout 0.118". Coverage tiles before waste comes to roughly 44 tiles at this size; with the default 10% waste factor, tiles to buy comes to about 49. Convert the room area result back to metric (multiply sq ft by 0.0929) to compare directly against a supplier's m² box-coverage listing.
Australian tile boxes are typically labeled with a coverage figure in m² per box rather than a tile count per box. Use the calculator's "coverage per box" field the same way — just convert the supplier's quoted m²-per-box figure to square feet first (multiply by 10.764) before entering it, and the boxes needed result will come out correct directly: boxes = ceil(room area in sq ft × (1 + waste) / (box coverage in sq ft)).
Because AU suppliers quote almost everything in m² (room area on a plan, tile size, box coverage) while this calculator's fields are imperial, the conversion step happens on both ends — inputs going in, and the area/box results coming back out — rather than just once. Keeping a simple conversion reference (1 m² = 10.764 sq ft, 1m = 3.281 ft) open alongside the calculator avoids mixing up which direction a given number needs to convert.
Australian tilers commonly quote the same 10% waste guideline for straight/offset layouts that this calculator defaults to, rising to 15–20% for diagonal layouts or patterned/rectified large-format tile with tight tolerance — consistent with the diagonal layout guide's reasoning, just expressed in the local market's own conventions.