WACC 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

t4-176

Effect

Computation or source lookup only

Input and validation requirements

The denominator V=E+D can be zero, producing an undefined WACC, and the specification does not define unit handling for percentage inputs, allowing radically different results.

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": {
    "equity_value": 600000000,
    "debt_value": 400000000,
    "cost_of_equity": 0.1,
    "cost_of_debt": 0.06,
    "tax_rate": 0.25
  },
  "expected_outputs": {
    "WACC_percent": 7.8
  },
  "working": "V=600,000,000+400,000,000=1,000,000,000. E/V=600,000,000/1,000,000,000=0.60. D/V=400,000,000/1,000,000,000=0.40. Equity contribution=0.60×0.10=0.060. After-tax debt contribution=0.40×0.06×(1−0.25)=0.40×0.06×0.75=0.018. WACC=0.060+0.018=0.078. As a percentage, 0.078×100=7.8%."
}

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