Drywall Sheet Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t5-102

Effect

Computation or source lookup only

Input and validation requirements

A zero sheet dimension produces division by zero and an undefined sheet count. The waste-percent convention also permits a large result discrepancy if the input is interpreted as a fraction instead of a percentage.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "surface": "walls",
    "area": 480,
    "area_unit": "ft²",
    "sheet_width": 4,
    "sheet_height": 8,
    "sheet_dimension_unit": "ft",
    "waste_percent": 10
  },
  "expected_outputs": {
    "sheets": 17
  },
  "working": "sheet_area = 4 × 8 = 32 ft²\nwaste multiplier = 1 + 10/100 = 1.10\nwaste-adjusted area = 480 × 1.10 = 528 ft²\nraw sheets = 528 ÷ 32 = 16.5\nsheets = ceil(16.5) = 17"
}

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-tranche5/tranche5-results.json