Balloon Payment Amortization Schedule Calculator

A balloon payment amortization schedule shows the regular payments due during a loan and the large remaining balance due at the end. Enter the loan amount, APR, term, and number of regular monthly payments to estimate that final balloon payment, total paid, and interest.

Formula

The calculator models a fixed-rate loan as if it were fully amortized over the stated term, then calculates the balance remaining after the specified number of regular payments. That remaining balance is the estimated balloon due immediately after payment k.

• Monthly rate, r = APR / 1200.
• Scheduled payment, PMT = round[P × r / (1 − (1 + r)⁻ⁿ), 2].
• Balance after k payments, B = P × (1 + r)^k − PMT × [(1 + r)^k − 1] / r.
• Total paid = k × PMT + B; estimated interest = total paid − P.

P is the original loan principal in dollars, APR is the annual percentage rate entered as a percent, n is the full amortization term in months (years × 12), k is the count of regular monthly payments before the balloon, and B is the balloon balance in dollars. The calculator requires k not to exceed n. At k = n, the balance should be approximately zero, subject to cent rounding.

Worked Example

Using the defaults: P = $20,000, APR = 8%, term = 5 years (60 months), and k = 59 regular payments.

1. Monthly rate: r = 8 / 1200 = 0.0066667.
2. Scheduled payment: round[$20,000 × 0.0066667 / (1 − (1.0066667)⁻⁶⁰), 2] = $405.53.
3. Balance after 59 payments: $20,000 × (1.0066667)⁵⁹ − $405.53 × [(1.0066667)⁵⁹ − 1] / 0.0066667 = $404.65 (rounded to cents).
4. Total paid including the balloon: 59 × $405.53 + $404.65 = $24,330.92.
5. Estimated interest: $24,330.92 − $20,000 = $4,330.92.

The balance calculation uses the rounded scheduled payment, matching the calculator. Small differences from a lender’s schedule can arise because actual payment dates, daily interest accrual, and rounding conventions may differ.

Assumptions

• The interest rate remains fixed throughout the modeled period.
• Regular payments are monthly and made at the end of each month; the balloon is paid immediately after the kth regular payment.
• Interest compounds monthly at APR / 12.
• Fees, taxes, insurance, escrow, late charges, and any lender-specific payment adjustments are not included.

How a Balloon Schedule Works

A standard fully amortizing loan spreads repayment of principal and interest across all scheduled payments, leaving no principal balance at the end if payments are made as assumed. A balloon loan instead sets regular payments using a shorter payment period or another contract structure, so those installments do not pay off all principal. The unpaid balance becomes due as a lump sum on the specified date.

A schedule typically lists each payment date, beginning balance, interest charged, principal repaid, ending balance, and the final balloon. In an ordinary monthly amortization row, interest is calculated on the outstanding balance, and the remainder of the installment reduces principal. Early in the schedule, interest can make up a larger portion of each level payment; as the balance declines, the principal portion generally grows.

This calculator uses the common structure in which regular installments are calculated for the full stated amortization term, but the balloon is due after k payments. A contract may instead calculate installments using a different payment schedule, use a variable rate, or define a particular payoff date. In those cases, the contract’s own schedule is needed for an exact figure.

How to Use and Read the Result

• Enter the principal, annual APR, and full amortization term in years.
• Enter the number of monthly installments that occur before the balloon is due. For example, 59 means 59 regular payments, followed by the remaining balance.
• Read the balloon output as an estimated principal-and-interest balance, not as an additional regular installment.
• Use total paid and interest as estimates for the modeled payments plus balloon; they exclude any unmodeled charges.

Check the payment count against the calendar and the loan documents. A loan described as having a five-year term does not necessarily mean 60 regular payments precede the balloon; the due date and first payment date determine the actual count. A zero count is mathematically permitted, but it means the modeled balloon is due before any regular installment.

Common Questions and Limitations

A balloon payment is not automatically the same amount as the original principal. Payments usually reduce the balance over time, while interest accrues, so the remaining balance depends on the APR, payment amount, timing, and number of installments. Nor is the balloon necessarily the last scheduled monthly payment: it is the separate payoff amount remaining after the specified regular payments.

The displayed amount is a mathematical estimate, not a payoff quote. A lender may calculate interest through the actual payoff date and include contractually applicable charges. Also, the calculator assumes one fixed rate and regular end-of-month payments. It cannot reproduce irregular payment dates, rate changes, payment holidays, extra principal payments, or a contract’s special rounding rules.

To compare this estimate with a disclosure or statement, confirm the principal, APR, term, payment count, and date used to calculate the balloon. Ask the lender for the written payment schedule and the amount due on the relevant date; do not assume that refinancing or selling an asset will be available to cover a future balance.

Frequently Asked Questions

How do I calculate a balloon payment?
Calculate the regular monthly payment at the stated APR and amortization term, then calculate the balance remaining after the regular payments made before the balloon. That remaining balance is the estimated balloon under those assumptions.

Is a balloon payment the same as the loan balance?
It is generally the remaining amount due at the balloon date, but the actual payoff figure can differ if interest has accrued since the last installment or additional charges apply. The contract and lender payoff quote establish the amount due.

Does a balloon payment include interest?
The modeled balance reflects the principal remaining after scheduled payments and the interest assumptions built into the amortization calculation. Any interest accruing between the last regular payment and the actual due date is not separately modeled here.

What happens if I set the number of payments equal to the full term?
The calculated balance should be close to zero because the regular payment is based on fully amortizing the loan over that term. Small differences can result from rounding the monthly payment to cents.

Why is my lender’s balloon amount different?
Possible reasons include a different payment count, actual-day interest, different payment dates, extra payments, a variable rate, fees, or different rounding. Compare the assumptions and ask the lender for an itemized schedule.

This result is an estimate, and the lender’s disclosure gives the exact figures.

Related

• When Will I Get My First JSA Payment?
• When Is Interest Paid on T-Notes? Payment Dates Explained
• Payments First: Meaning and Loan Payment Calculator

in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
in k | Regular monthly payments before balloon | - | 59 | 0 | 599
out bal | Balloon payment after k payments | $ | p * (1 + apr / 1200) ^ k - round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) * ((1 + apr / 1200) ^ k - 1) / (apr / 1200) + 0 * sqrt(yrs * 12 - k) | 2
out pmt | Scheduled monthly payment | $ | round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out tot | Total paid including balloon | $ | pmt * k + bal | 2
out int | Interest paid including balloon | $ | tot - p | 2