Balloon payment calculator
Work out the balloon left on a loan when regular payments stop before the loan is fully repaid. See the monthly payment, the interest paid, the balloon amount and the final payment, with the full schedule.
Loan amounts and payments up to 1000000000000 at 0 to 3 decimal places, 100000000000 at 4, 10000000000 at 5 and 1000000000 at 6, with the monthly payment and every month-end balance within 1000000000000000 minor currency units (10000000000000 at 2 decimal places), APRs from 0 to 100 percent, amortization terms and balloon months from 1 to 1200. Calculated locally in your browser. Downloads are a JSON report and a CSV with one row per month. This calculator reads the form fields below; there is no text box. Up to 1,000,000 characters. Review the settings before running.
Your result
How to use Balloon payment calculator
- Enter the loan amount and the interest rate.
- Choose whether the payment comes from an amortization term or from a payment you enter.
- Enter the amortization term or the payment, and the month the balloon is due.
- Review the balloon, final payment and totals, then download the JSON report or the monthly CSV.
Useful next steps
Method
In amortization mode the monthly payment is the level payment that would repay the loan over the amortization term, P times r divided by 1 minus (1 + r) to the power of minus n, with r the APR divided by 12. This is the same formula as the spreadsheet PMT function (Microsoft Support, PMT function, checked 16 October 2026). Payments then run until the balloon month, and the balloon is the balance left after the last regular payment. A balloon payment is a large final payment due at the end of a loan, as described by the Consumer Financial Protection Bureau (What is a balloon payment, checked 16 October 2026).
Payment mode
When you enter the payment yourself, it must be at least one month of interest so the balance never grows. A payment equal to the interest gives an interest-only loan whose balloon is the whole loan amount. If the payments repay the loan before the balloon month, the report shows the payoff month and no balloon.
Rounding and limits
Interest is rounded to the cent each month, half away from zero, and amounts are exact in minor currency units. When the balloon month equals the amortization term the last payment is adjusted so the balance ends at exactly zero. Fees, rate changes and refinancing are not included. This is a calculation from your own numbers, not financial advice.