Calculate simple interest plus separately entered borrowing fees over a stated time.
The calculator keeps the balance, rate convention, payment timing, fees, and term visible so you can reproduce the result and compare it with an actual offer or statement.
The cash-flow relationship
Place every amount at the correct time
Finance charge = balance × nominal annual rate × months/12 + entered fees, using the rates as decimal fractions.
Visual explanation
What changes the borrowing result
Balance / proceedscash charge or interestTime / limit basisExplicit rate or finance chargeFinance charge = balance × nominal annual rate × months/12 + entered fees, using the rates as decimal fractions.
Read the result in context
Use the estimate with its contract assumptions
On 10,000 at 12% for 6 months, simple interest is 600; adding 100 of entered fees gives a 700 finance charge.
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.
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.
