Balloon Loan Calculator: Monthly Payment and Balloon Amount

This calculator works out a balloon loan: payments are set as if the loan ran for the full amortization period, but the balance still owed falls due as one lump sum at an earlier date. Enter the amount, the APR, the amortization period and when the balloon is due.

Formula

Monthly payment M = P × r ÷ (1 − (1 + r)⁻ⁿ) over the amortization period n. Balloon = B_k = P(1 + r)^k − M((1 + r)^k − 1) ÷ r, the balance after k payments.

Worked Example

$30,000 at 7% APR, amortized over 10 years, balloon due after 60 months.

1. r = 0.005833, n = 120, M = $348.33
2. Balance after 60 payments = $17,591.13, which is the balloon
3. Total paid = 348.3254 (the exact payment) × 60 + 17,591.13 ≈ $38,490.66; at the rounded $348.33 a month it is a few cents more

Assumptions

• Results use the exact level payment before rounding to the cent; a lender’s cent-rounded schedule can differ by a few cents.
• Fixed interest rate for the whole term; payments of equal size at the end of each month.
• Interest compounds monthly at APR ÷ 12.
• No fees, taxes or insurance unless the calculator has a field for them.
• The balloon is paid with the last regular payment; no refinancing is assumed.

How to read the result

The balloon is usually a large share of the loan. Plan how it will be paid (savings, a sale or a new loan) before the date it falls due.

Limits and common mistakes

• The balloon month must not be later than the amortization period.
• Some balloon contracts are interest-only; use the interest-only calculator for those.

Frequently Asked Questions

How big is the balloon on $30,000 at 7%, 10-year amortization, due in 5 years?

About $17,591, after 60 payments of about $348.33.

Why is the monthly payment lower than a 5-year loan?

It is calculated over 10 years, so less principal is repaid each month.

What happens if I cannot pay the balloon?

That depends on your contract and lender; ask them before signing.

in p | Loan amount | $ | 30000 | 1 | 100000000
in apr | Interest rate (APR) | % | 7 | 0.01 | 100
in yrs | Amortization period | years | 10 | 1 | 50
in k | Balloon due after | months | 60 | 1 | 600
out bal | Balloon payment | $ | max(0, p * (1 + apr / 1200) ^ k - p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) * ((1 + apr / 1200) ^ k - 1) / (apr / 1200)) + 0 * sqrt(yrs * 12 - k) | 2
out pmt | Monthly payment | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out tot | Total paid including the balloon | $ | pmt * k + bal | 2