Quick guide
How to use this calculator
- Enter the balances, rates, fees, and timing requested by the visible labels.
- Keep monetary entries in one consistent currency.
- Review the result together with the declared calculation convention and exclusions.
Calculation method
Calculation method
Finance charge = balance × nominal annual rate × months/12 + entered fees, using the rates as decimal fractions.
Entered fixed decimals are aggregated exactly. Iterative rate solving is bounded to a single nonnegative monthly cash-flow root and fails explicitly if the result is absent, too large, or not reliably representable.
Worked example
Worked example
On 10,000 at 12% for 6 months, simple interest is 600; adding 100 of entered fees gives a 700 finance charge.
Finance charge = balance × nominal annual rate × months/12 + entered fees, using the rates as decimal fractions.
Supported inputs
Precision and limits
Visible input limits
Amounts are capped at 1e12, rates at 1000%, monthly periods at 1,200, and fixed decimals at 12 places. List tools accept 1–20 uniquely named rows.
Estimate, not a disclosure
Results model only the entered convention. They do not reproduce a lender statement, credit score, underwriting outcome, or jurisdiction-specific consumer-credit disclosure.
International scope
No currency, country, credit bureau, scoring model, statutory APR rule, fee classification, grace period, or issuer policy is assumed.
Calculator-specific assumptions
The calculator uses simple interest on an unchanged balance. It is not an amortizing-loan schedule or a legal classification of which charges must appear in a disclosure.