🏢 Commercial Mortgage Calculator with Balloon Payment
By Shihab Mia · Updated 2026-07-09
This commercial mortgage calculator gives an estimate for education and planning only and is not financial, lending, or tax advice. Actual rates, fees, and balloon terms depend on your lender, the property, and your business, so confirm every figure with a licensed commercial lender before signing.
Loan details
How the payment is spread out. 25 is common.
When the remaining balance is due. 5 to 10 is typical.
This commercial mortgage calculator shows your monthly payment, the balloon payment due at the end of the loan term, and the total interest you pay along the way. Most commercial mortgages are amortized over a long period, such as 25 years, but the loan term is much shorter, often 5 to 10 years, so a large lump-sum balloon comes due when the term ends. Enter your loan amount, interest rate, amortization period, and loan term, and the tool returns all four numbers instantly so you can plan for the refinance or payoff before it arrives.
What is the Commercial Mortgage Calculator?
A commercial mortgage is structured very differently from a home loan, and that difference is exactly what this commercial mortgage calculator is built to expose. On a typical residential loan, the amortization period and the loan term are the same: pay for 30 years and the balance reaches zero. On a commercial mortgage, the two numbers are deliberately split. The monthly payment is calculated as if the loan will be paid off over a long amortization period, commonly 20 to 30 years, which keeps the payment affordable. But the loan term, the point at which the lender wants their money back, is much shorter. When that term ends, the balance that has not yet amortized is due all at once. That lump sum is the balloon payment.
The math runs in two steps. First, the calculator finds the monthly payment using the standard amortization formula over the full amortization period: payment = P times r divided by (1 minus (1 + r) to the power of negative N), where P is the loan amount, r is the monthly interest rate (APR divided by 12 divided by 100), and N is the number of months in the amortization period. Second, it computes the remaining balance after the shorter loan term using the balance formula: balance = P times (1 + r) to the power of m, minus payment times (((1 + r) to the power of m minus 1) divided by r), where m is the number of months in the loan term. That remaining balance is the balloon.
Why does this structure exist? Lenders limit their interest-rate risk by keeping terms short, while borrowers get a manageable monthly payment based on a long amortization. The trade-off is the balloon: at the end of the term the borrower must refinance, sell the property, or pay the balance in cash. A commercial mortgage calculator that ignores the balloon dramatically understates the real obligation, which is why this tool reports the balloon, the monthly payment, the total paid during the term, and the total interest during the term side by side.
Use the results to pressure-test a deal. If the balloon is $775,000 on a $1,000,000 loan after a 10-year term, you know most of the principal is still outstanding when the term ends, because a 25-year amortization only chips away slowly in the early years. Model a shorter amortization to see the balloon shrink, or a higher rate to see how refinancing risk grows. This commercial mortgage calculator is a planning tool for that refinance moment, not a substitute for a lender quote, but it gets the structure and the numbers right so your projections start from solid ground.
When to use it
- Estimating the monthly payment and balloon on a commercial real estate purchase before you approach a lender.
- Planning ahead for the refinance or sale that must cover the balloon payment when the loan term ends.
- Comparing a 20-year versus 25-year versus 30-year amortization to see how each changes the payment and the balloon.
- Stress-testing a deal against a higher interest rate to gauge refinancing risk on a variable or resetting loan.
- Underwriting an investment property by checking that rental income comfortably covers the monthly payment.
- Comparing lender offers that use different terms and amortization schedules on the same loan amount.
How to use the Commercial Mortgage Calculator
- Enter the loan amount you plan to borrow for the commercial property.
- Enter the interest rate (APR) the lender quoted, as an annual percentage.
- Set the amortization period in years. This spreads out the payment. 25 years is a common default.
- Set the loan term (balloon) in years. This is when the remaining balance comes due, often 5 to 10 years.
- Read the monthly payment, the balloon payment, the total paid during the term, and the total interest during the term.
Formula & method
Worked examples
You borrow $1,000,000 at 6.5% APR, amortized over 25 years, with a 10-year loan term and balloon.
- Monthly rate r = 6.5 ÷ 100 ÷ 12 = 0.00541667
- Amortization months N = 25 × 12 = 300, so PMT = 1,000,000 × 0.00541667 ÷ (1 − 1.00541667^-300) = 6,752.07
- Term months m = 10 × 12 = 120
- Balloon = 1,000,000 × 1.00541667^120 − 6,752.07 × ((1.00541667^120 − 1) ÷ 0.00541667) = 775,113.59
- Total paid during term = 6,752.07 × 120 + 775,113.59 = 1,585,362.19; interest = 585,362.19
Result: Monthly payment about $6,752.07, balloon about $775,114 due after 10 years, $585,362 interest during the term
You borrow $750,000 at 7.25% APR, amortized over 20 years, with a 7-year loan term.
- Monthly rate r = 7.25 ÷ 100 ÷ 12 = 0.00604167
- N = 20 × 12 = 240, so PMT = 750,000 × 0.00604167 ÷ (1 − 1.00604167^-240) = 5,927.82
- Term months m = 7 × 12 = 84
- Balloon = 750,000 × 1.00604167^84 − 5,927.82 × ((1.00604167^84 − 1) ÷ 0.00604167) = 597,760.70
Result: Monthly payment about $5,927.82, balloon about $597,761 due after 7 years, $345,698 interest during the term
Balloon payment on a $1,000,000 loan at 6.5% APR after a 10-year term, by amortization period
| Amortization | Monthly payment | Balloon after 10 years |
|---|---|---|
| 20 years | $7,455.73 | $656,615 |
| 25 years | $6,752.07 | $775,114 |
| 30 years | $6,320.68 | $847,761 |
Payment and balloon on a $1,000,000 loan, 25-year amortization, 10-year term, by rate
| Interest rate (APR) | Monthly payment | Balloon after 10 years |
|---|---|---|
| 5.5% | $6,140.87 | $751,560 |
| 6.5% | $6,752.07 | $775,114 |
| 7.5% | $7,389.91 | $797,175 |
| 8.5% | $8,052.27 | $817,706 |
Common mistakes to avoid
- Confusing the amortization period with the loan term. The amortization period sets how small the monthly payment is; the loan term sets when the balance is due. On a commercial mortgage they are different numbers. A 25-year amortization with a 10-year term does not pay the loan off in 10 years, it leaves a large balloon.
- Forgetting to plan for the balloon payment. The comfortable monthly payment can lull you into ignoring the lump sum at the end. On a 25-year amortization, most of the principal is still outstanding after 10 years. Line up a refinance, sale, or cash reserve well before the term ends.
- Assuming you can always refinance the balloon. Refinancing depends on property value, your credit, and market rates at the time the balloon is due. If values drop or rates spike, refinancing may be costly or unavailable. Model a higher rate here to see how exposed you are.
- Ignoring fees, taxes, and insurance. This calculator shows principal and interest only. Commercial loans often add origination fees, appraisal costs, property taxes, and insurance. Your true monthly cost and cash to close will be higher, so budget beyond the payment shown.
Glossary
- Commercial mortgage
- A loan secured by commercial property such as an office, retail, industrial, or multifamily building, usually with a short term and a longer amortization.
- Amortization period
- The length of time used to calculate the monthly payment as if the loan would be fully paid off, commonly 20 to 30 years on commercial loans.
- Loan term
- The actual length of the loan before the remaining balance is due. On a commercial mortgage this is shorter than the amortization period, often 5 to 10 years.
- Balloon payment
- The lump-sum remaining balance due at the end of the loan term because the payment was based on a longer amortization than the term.
- APR
- The annual percentage rate. Divided by 12 it gives the monthly rate used to compute the payment and the remaining balance.
- Remaining balance
- The principal still owed at any point in the loan. After the loan term this remaining balance equals the balloon payment.
Frequently asked questions
How is a commercial mortgage payment calculated?
The monthly payment uses the standard amortization formula over the amortization period: payment = P times r divided by (1 minus (1 + r) to the power of minus N), where P is the loan amount, r is the APR divided by 12 divided by 100, and N is the amortization months. On a $1,000,000 loan at 6.5% over 25 years, the payment is about $6,752.07 per month.
What is a balloon payment on a commercial mortgage?
A balloon payment is the remaining loan balance due in one lump sum at the end of the loan term. Because the monthly payment is based on a long amortization (say 25 years) but the term is short (say 10 years), most of the principal is still owed when the term ends. On a $1,000,000 loan at 6.5% with a 25-year amortization and 10-year term, the balloon is about $775,114.
What is the difference between amortization period and loan term?
The amortization period is the schedule used to size the monthly payment, commonly 25 years. The loan term is when the lender wants the balance repaid, commonly 5 to 10 years. On a commercial mortgage these differ, so the loan is not paid off at the end of the term and a balloon payment is due.
How do I calculate the balloon payment myself?
Use balance = P times (1 + r) to the power of m, minus payment times (((1 + r) to the power of m minus 1) divided by r), where m is the number of months in the loan term and r is the monthly rate. This calculator does it automatically when you enter the loan amount, rate, amortization, and term.
Why is the balloon payment so large after 10 years?
Because a long amortization pays down principal slowly in the early years, most of what you owe is still outstanding when a short term ends. Early payments are mostly interest. On a 25-year amortization, after 10 years roughly three quarters of the original principal can remain, which becomes the balloon.
What happens when the balloon payment comes due?
You typically refinance into a new loan, sell the property to pay off the balance, or repay it in cash. If you cannot do any of these, you risk default. Plan the exit well before the term ends, and model a higher rate here to see how a tougher refinancing market would affect you.
Sources
- What is a balloon payment? When is one allowed? , Consumer Financial Protection Bureau
- Commercial Real Estate Loan , Investopedia