Loan Amortization With Balloon Payment Calculator

A loan amortization with balloon payment calculator estimates the regular monthly payment on a loan and the large remaining balance due at the end of a shorter payment period. Enter the loan amount, APR, and amortization term; the results show the monthly payment, total paid, and balloon balance after the specified number of payments.

Formula

This calculator uses a standard fixed-rate amortization schedule to find the scheduled payment, then calculates the unpaid balance after the selected number of monthly payments. It assumes the balloon date occurs after a whole number of monthly payments.

• Monthly rate: r = APR / 1200, where APR is the annual percentage rate entered as a percentage.
• Number of scheduled payments: n = amortization term in years × 12.
• Monthly payment: M = round[P × r / (1 − (1 + r)⁻ⁿ), 2].
• Balloon balance after k payments: B = P × (1 + r)^k − M × [(1 + r)^k − 1] / r.
• Total paid through the balloon date: M × k + B.
• Interest paid through that date: M × k + B − P.

P is the original principal in dollars, r is the monthly interest rate as a decimal, M is the monthly payment in dollars, n is the full amortization schedule in months, and k is the number of payments made before the balloon is due. The payment is rounded to cents before the balance and totals are calculated, so small rounding differences from a lender’s schedule can occur.

Worked Example

Using the defaults: principal P = $20,000, APR = 8%, amortization term = 5 years, and balloon after k = 36 months:

1. Convert APR to a monthly rate: r = 8 / 1200 = 0.0066667, or about 0.66667% per month.
2. Calculate the scheduled payment over 5 × 12 = 60 months: M = round[$20,000 × 0.0066667 / (1 − (1.0066667)⁻⁶⁰), 2] = $405.53 per month.
3. Find the balance after 36 payments: B = $20,000 × (1.0066667)³⁶ − $405.53 × [(1.0066667)³⁶ − 1] / 0.0066667 = $9,172.15, rounded to cents.
4. Add 36 payments and the balloon: 36 × $405.53 + $9,172.15 = $23,771.23 total paid.
5. Subtract the original principal: $23,771.23 − $20,000 = $3,771.23 interest paid through the balloon date.

The balance is not the same as the final scheduled payment. It is the principal and accrued interest still due after the regular payments included in the calculation. The lender’s actual payoff figure may also reflect payment timing, rounding, or contract-specific charges not represented here.

Assumptions

• The interest rate is fixed for the calculation period.
• Payments are equal monthly payments made at the end of each month.
• Interest compounds monthly at APR divided by 12; no daily-interest convention is modelled.
• The calculator treats the balloon as the remaining scheduled balance immediately after the selected payment.
• Fees, taxes, insurance, PMI, escrow, late charges, and any separate balloon fee are not included.

How Amortization and a Balloon Payment Work

Amortization means that each scheduled payment covers interest for the period and reduces principal according to a repayment schedule. Early in a loan, a larger share of a level payment generally goes to interest because the balance is larger; as principal falls, the interest portion falls too. A balloon loan uses this familiar payment calculation but requires repayment before the full amortization schedule has run its course.

For example, a loan can be calculated as if it would be repaid over five years but require a final payment after three years. The monthly amount is based on the five-year schedule, not on paying the entire loan off in three years. Consequently, a balance remains after 36 payments. That remaining amount is the balloon payment, subject to the agreement’s exact payoff calculation.

The phrase “balloon payment” can describe different contract structures. Some loans specify a fixed balloon amount; others define it as the unpaid balance on a certain maturity date. This calculator models the second case: the remaining balance after a chosen number of monthly payments. Check the contract to confirm whether its balloon amount is fixed, calculated from a schedule, or adjusted by other terms.

Reading the Results and Choosing Inputs

The monthly payment is the scheduled amount implied by the amortization term and APR. The balloon balance estimates the lump sum due after the chosen number of payments. “Payments made plus balloon” adds those regular payments to the final balance; it does not include payments that would have been made after the balloon date. Interest paid is calculated as those amounts minus the original principal.

• Enter the principal amount borrowed, not the amount you expect to receive after deductions unless that is also the contract’s principal.
• Use the APR stated in the loan documents as a percentage, such as 8 for 8%, rather than entering 0.08.
• Enter the amortization term used to set the monthly payment. Do not substitute the time until the balloon unless both periods are the same.
• Set “Balloon after” to the number of monthly payments made by the balloon date. It must be a whole number and should not exceed the amortization term’s months.

The calculator’s input ranges allow the balloon month to exceed the amortization schedule in order to keep the form simple, but that is not a meaningful standard balloon scenario: after the scheduled term, the modeled balance may be zero or may not represent a contract payoff. Use a balloon month no later than the scheduled term and confirm the relevant dates in the loan agreement.

Common Misunderstandings and Limits

A lower monthly payment does not mean the loan costs less overall. With a balloon structure, principal can remain unpaid until maturity, and the borrower must be prepared for the final lump sum under the contract. The balloon is not automatically the original principal minus payments: interest accrues on the declining balance, so the balance formula accounts for both interest and principal reduction.

Another common mistake is treating the amortization term as the balloon date. They are different inputs: the term determines the scheduled payment, while the balloon month determines when the remaining balance is calculated. Also, the calculator rounds each monthly payment to cents and uses that rounded amount in its balance calculation. A lender’s ledger may use a different rounding convention, exact payment dates, or a daily accrual method, causing a modest difference.

This is an estimate, not a full loan contract or payoff statement. It does not account for variable rates, skipped or extra payments, irregular first periods, fees, or contract terms that change the amount due. For the contractual due date, payoff amount, and any amount required to satisfy the obligation, consult the lender’s disclosure and loan documents.

Frequently Asked Questions

What is a balloon payment on an amortizing loan?
It is a large final payment that covers the remaining balance when regular payments have not fully repaid the loan by the balloon date.

How do I calculate the balloon balance?
First calculate the regular payment from the principal, rate, and full amortization term. Then apply the balance formula after the number of payments made before the balloon date.

Is the balloon payment the same as the last monthly payment?
No. The scheduled monthly payment is usually a regular installment. The balloon is a separate, much larger amount representing the outstanding balance due at maturity.

Why is there still a balance after years of payments?
The payment schedule may be based on a longer amortization period than the time before the balloon comes due. Payments reduce the debt, but do not fully pay it off by the earlier maturity date.

Does this estimate include fees or the exact payoff amount?
No. It models principal and interest under the assumptions above. Fees, payment-date interest, and contract-specific adjustments must be checked in the lender’s payoff information.

This result is an estimate for educational purposes; the lender’s disclosure gives the exact figures.

Related

• Create a Loan Amortization Schedule
• Daily Interest Loan Amortization Calculator
• Commercial Loan Amortization Schedule Calculator

in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Amortization term | years | 5 | 0.0833 | 50
in bal | Balloon after | months | 36 | 1 | 600
out pmt | Monthly payment | $ | round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out due | Balloon balance after selected months | $ | p * (1 + apr / 1200) ^ bal - pmt * ((1 + apr / 1200) ^ bal - 1) / (apr / 1200) | 2
out paid | Payments made plus balloon | $ | pmt * bal + due | 2
out int | Interest paid through balloon date | $ | pmt * bal + due - p | 2