Print DPI / Size 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

t4-217

Effect

Computation or source lookup only

Input and validation requirements

A zero-DPI input makes the core division undefined, and the specification provides no stated validation or rejection rule. Unit ambiguity can also produce materially different dimensions if DPI is confused with pixels per centimetre.

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": {
    "mode": "print_size",
    "pixel_width": 6000,
    "pixel_height": 4000,
    "dpi": 300
  },
  "expected_outputs": {
    "print_width_in": 20,
    "print_height_in": 13.3333333333,
    "print_width_cm": 50.8,
    "print_height_cm": 33.8666666667
  },
  "working": "Width: 6000 ÷ 300 = 20 in. Height: 4000 ÷ 300 = 13.3333333333 in. Width in cm: 20 × 2.54 = 50.8 cm. Height in cm: 13.3333333333 × 2.54 = 33.8666666667 cm."
}

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