Measure the tiled footprint
Break irregular floors into simple zones and exclude only areas that truly will not receive tile.
Include thresholds, closets, alcoves, and connected areas using the same material.
Test layout before waste
Centered grids, diagonals, borders, multiple sizes, and narrow perimeter cuts change offcut reuse.
A layout sketch is more informative than one generic waste percentage.
Convert area to pieces and boxes
Theoretical pieces can use tile face area, but procurement should use manufacturer pieces-per-box or carton coverage.
Round final package count upward.
Keep trim and setting materials separate
Bullnose, profiles, thresholds, mortar, grout, membranes, and leveling products have different coverage rules.
Do not bury them inside the tile-box allowance.
Verify the selected tile system
Substrate, mortar, movement accommodation, joint width, rating, and large-format requirements are installation issues.
Use selected product instructions before purchase.