Tile & Flooring Calculator mechanism

Model scope

The core area, waste, tile-count, and box-count arithmetic is standard under the stated unit assumptions. Approval requires an explicit diagonal-layout rule, a defined percentage representation, consistent handling of box coverage versus tiles_per_box, and a grout-estimate formula with its required inputs. The honest label should state that 10% and 15% waste values are rules of thumb and that actual waste depends on cuts, room geometry, tile size, and layout.

• The tile-count formula is standard if waste% means a percentage converted to a decimal: ceil(room_area × (1 + waste_percent/100) / tile_area). The notation 1+waste% is ambiguous in implementation.
• The stated diagonal-layout adjustment is not present in the formula. It is only implied through a default waste factor of 15%, so the layout toggle must explicitly map straight to 10% and diagonal to 15%, unless the user overrides waste.
• The specification accepts box coverage, but the formula requires tiles_per_box. A conversion is missing: tiles_per_box = box_coverage / tile_area, with compatible units.
• Grout estimate is listed as an output but has no formula or required inputs such as grout-joint width, tile thickness, grout depth, coverage rate, or grout packaging.
• The formula does not state whether room dimensions and tile dimensions may use different units or how conversions are performed.

Units and conventions

• All area quantities in each calculation must use the same area unit before division.
• waste_percent is interpreted as percentage points: 10 means 10%, so the multiplier is 1 + 10/100 = 1.10.
• Tile area is calculated as tile_length × tile_width after converting both dimensions to the same length unit.
• If box coverage is used instead of tiles_per_box, box coverage must use the same area unit as room area and tile area.
• ceil is applied to tile count before dividing by tiles per box, as specified.
• The diagonal default is assumed to be 15% and the straight-layout default 10% for these test vectors.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "room_length_ft": 12,
    "room_width_ft": 10,
    "tile_length_in": 12,
    "tile_width_in": 12,
    "waste_percent": 10,
    "layout": "straight",
    "tiles_per_box": 10
  },
  "expected_outputs": {
    "room_area_sq_ft": 120,
    "tile_area_sq_ft": 1,
    "tiles": 132,
    "boxes": 14
  },
  "working": "1. Room area = 12 ft × 10 ft = 120 ft². 2. Tile area = 12 in × 12 in = 1 ft × 1 ft = 1 ft². 3. Waste-adjusted area = 120 × (1 + 10/100) = 120 × 1.10 = 132 ft². 4. Tiles = ceil(132 / 1) = ceil(132) = 132. 5. Boxes = ceil(132 / 10) = ceil(13.2) = 14."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The specification permits a zero tile area that causes division by zero, does not define validation for zero room area, and provides no formula or required inputs for the grout estimate.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json