Balloon payment calculator

What this calculator computes

A balloon note splits the payment size from the payoff date. Payments are sized as if the loan amortized over its full term — thirty years, say — but the note matures much earlier, and on the balloon date the entire remaining balance comes due in a single payment. It is the common shape of owner-financed paper: the buyer gets an affordable monthly payment, and the seller gets paid out in five or ten years instead of thirty. This calculator shows every scheduled payment up to the balloon month and the exact balloon amount — which is always far larger than the monthly payment, and which every figure on this page comes from the same engine that runs OwnerNote, with no arithmetic done in the page itself.

What each input means

Principal is the amount financed.Annual rate is the note's fixed yearly rate, to six decimal places. Amortization term is the number of months the payment is sized on — not how long the note actually runs. Balloon month is when the note matures and the remaining balance is due; it must fall after the first payment and before the end of the amortization term, or the balloon is meaningless. Origination date andfirst payment date anchor the schedule in time.

Day count convention is an explicit choice, not a default, because a silently wrong convention is unrecoverable — every interest figure and every balance after the first payment depends on it, including the balloon amount itself. The two options are30/360 Bond Basis, where each monthly period counts as one-twelfth of a year, and Actual/365 fixed, where interest accrues on actual calendar days. The note's payment clause states which one governs; pick that one, and the result shows the choice so anyone reading it can check the work.

A worked example

Take a $180,000.00 note at 7.00% fixed, amortized over 360 months with a balloon at month 60, originated January 1, 2026, first payment due February 1, 2026, on a 30/360 Bond Basis day count. The monthly payment is sized on the full 360-month amortization:$1,197.54. Payment 1's interest is $180,000 × 7% ÷ 12 = $1,050.00, so $147.54 reaches principal and the balance falls to $179,852.46. The schedule runs 60 rows, not 360.

At month 60 — due January 1, 2031 — the note matures. That row's interest is $989.60, and its principal is not the ordinary amortizing sliver but the entire remaining balance, $169,645.10. The balloon payment due is $170,634.70, not $1,197.54. That is the figure this calculator exists to surface, because it is the one that catches people: after five years of on-time payments on a $180,000.00 note, the balance still standing at maturity is $169,645.10, and all of it is due at once.