Calculation Methodology

How calculations are produced

Every calculator runs locally in your browser. Inputs are passed to deterministic TypeScript functions, so the same values and settings produce the same result. Displayed figures are rounded for readability; calculations use the full JavaScript number precision until the final formatting step.

Loan and mortgage payments

Fixed-rate payments use the standard amortization formula: payment = principal × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where r is the periodic interest rate and n is the number of payments. Taxes, insurance, fees, and extra payments are displayed separately when a tool includes them.

Savings and compound interest

Growth projections compound the starting balance at the selected frequency and add regular contributions over the selected period. Rates are user-provided assumptions, not live quotes or forecasts. Actual returns, taxes, fees, and inflation can materially change the outcome.

Salary estimates

Salary results convert annual gross pay into monthly, weekly, and hourly equivalents. The tax field is an effective-rate assumption supplied by the user; CalcPilot does not calculate jurisdiction-specific payroll taxes or replace an official payroll estimate.

Unit conversions

Each converter publishes its factor or formula beside the result. Ratio conversions multiply or divide by a fixed factor. Temperature conversions also apply the required offset. The data converter explicitly uses binary units, where 1 GB equals 1,024 MB.

Verification and corrections

Worked examples, boundary cases, and inverse conversions are checked during development. The source code is public, so formulas can be independently reviewed. If a result looks wrong, include the calculator name, inputs, expected result, and a reliable reference in a GitHub issue.

Last reviewed: August 14, 2026. Results are estimates for planning and educational use only. See the Disclaimer before making financial, legal, tax, health, or other consequential decisions.