What problem this solves
Tile estimators that return “area × 1.10” work for a simple grid but undersell herringbone, chevron, and other patterns. The waste from a herringbone install is significantly higher because each border tile needs a diagonal cut, and the offcuts are usually too small to reuse. Industry-standard waste factors from the TCNA handbook give a much more accurate count: 10% for straight, 12% for brick, 15% for herringbone, 18% for chevron. The calculator applies the right factor per pattern.
Diagonal rooms (rooms with non-rectangular corners, alcoves, or angled walls) need an additional 5% on top of the pattern waste. This is separate from the pattern waste because it applies regardless of pattern — it’s a function of the room shape. The calculator asks for this and adjusts.
Who it’s for
- Tile installers quoting a job based on tile count
- Designers specifying tile quantity for an order
- Homeowners buying tile from a retailer that sells by the box
- Contractors verifying a supplier’s quote
Why pattern waste is real money
Tile waste is the silent cost of a patterned install. A 12 m² floor with a herringbone pattern needs ~15% extra tiles, which translates to roughly 1.8 m² of tiles you pay for but don’t use. At high-end tile prices (€50–100/m²), the difference between a 10% waste estimate and a 15% estimate is €60–120 on a single room. Across a whole house, it adds up. Better to order the right amount once than to discover on day three that you’re short by a box.
Limitations
- Waste factors assume a rectangular room with one or two obstacles.
- No special consideration for curved walls, niches, or diagonal sub-areas.
- Tiles are assumed whole — you may be able to reuse offcuts in corners but the calculator doesn’t optimse layout.
- Box count rounded up; partial boxes at the end may be returnable depending on supplier.
- Diagonal cuts flag assumes a rough guess; a measured room shape would be more accurate.
Practical rules of thumb
Always buy one full extra box beyond the calculator’s recommendation if the supplier allows returns — it covers the inevitable breakage (1–2% of tiles) and any pattern-matching decisions mid-install. Keep a few tiles from the original batch as spares for future repairs; tiles are often dye-batched and a 6-month-later reorder won’t match colour exactly.