Methodology & limitations
Understand what is calculated, what is entered, and what remains unknown.
Calculation rules
Measure the room, wall openings, and trim exclusions. Enter actual tile dimensions and packaging rather than nominal dimensions alone.
Calculate a conservative straight-lay grid, show centered edge pieces, add explicit allowance, and round to boxes.
Calculate wall-paint coverage and trim independently, then combine material costs in a staged purchase schedule.
Limits that matter
This is a finish-quantity estimate, not architectural, engineering, waterproofing, or code-compliance documentation. Verify the installation system before buying.
Entered measurements and prices
The starting room is illustrative. There is no connected manufacturer catalog or retail price feed. Measure the room and enter actual product dimensions, packaging, coverage and prices. JSON restore reads a previously exported plan on your device; CSV is a result export, not a catalog import.
Reproducible results
Export a JSON plan to preserve measurements, prices, project name and method version. The purchase CSV contains the complete staged schedule. The printable sheet includes the layout, material quantities, assumptions and limitations. Browser saves stay on this device until you delete them or clear storage. There is no automatic backup or cloud sync.
Corrections and commercial independence
Record anonymized inputs, the expected result, the actual result and the method version when reporting a calculation issue. Use the operator contact or public source link when configured. Never post private project information in a public issue. Advertising cannot change calculations or warnings.