Calculation Methodology

Financial inputs are processed locally in the browser. The engine is separate from page content. We use standard mathematical models, stable interest calculations and unrounded intermediate values. Amounts are rounded only for display. Display currency does not convert exchange rates.

This release uses JavaScript double-precision numbers and is an educational planning tool, not an accounting ledger. Undefined ratios are labelled, invalid values are rejected, and unsupported numerical ranges stop with an error. Loan schedules reconcile principal and interest. Fixed-rate growth is a scenario, not a market forecast. Automated reference tests, boundary checks and browser checks are recorded in the release report; production certification remains a separate final gate.

Policy updated: 14 October 2026.