Methodology · AU-DEBT-001
Loan Calculator
Estimate loan repayments, total interest and payoff date for personal loans with a full amortisation schedule and optional monthly fees.
Engines and formulas
- E11 · Amortising loan engine
Closed-form §13.5 payment (with §13.6 balloon), then a full §13.7 schedule with per-period cent rounding and a capped final-payment adjustment.
Registered formulas: §13.5 payment · §13.6 balloon · §13.7 recurrence
Verification
Engines carry boundary tests at every bracket edge, property-based tests, reconciliation invariants and, where official worked examples exist, tests that reproduce them exactly. The full source register is on the sources page.