An amortization schedule is the single most useful document for understanding what a commercial real estate loan actually costs over time, and it's also one of the most commonly misread in 2026. Borrowers frequently compare loans by monthly payment alone, without realizing that two loans with identical payments can leave you in very different equity positions five years in.
This is a plain breakdown of how amortization works, how balloon payments and interest-only periods change the math, and a worked example you can adapt to your own deal.
What is a loan amortization schedule?
A loan amortization schedule is a table showing each scheduled payment over the life of a loan, broken into the portion applied to interest and the portion applied to principal, along with the remaining balance after each payment. Early in a fully amortizing loan, most of each payment goes to interest because the outstanding balance is largest; as the balance shrinks, a growing share of each payment reduces principal. This is why paying off a loan a few years early saves far less than borrowers expect — most of the early payments were interest, not equity-building principal.
How does amortization affect what you actually owe over time?
Two loans with the same rate and payment can leave you owing very different balances at any point before maturity, depending on the amortization period used to calculate the payment — a 30-year amortization schedule on a 10-year loan term leaves a much larger remaining balance at year 10 than a 25-year amortization schedule would. This is standard in commercial lending: the amortization period (used to size the payment) is often longer than the loan term (when the balance actually comes due), which is exactly what creates a balloon payment.
What is a balloon payment and why do commercial loans use them?
A balloon payment is the large remaining principal balance due in a single lump sum at loan maturity, because the loan term is shorter than the amortization schedule used to calculate the monthly payment. Commercial lenders use balloon structures because they don't want to lock in today's rate for 25-30 years the way a residential mortgage does — a 10-year loan term with a 25 or 30-year amortization schedule gives the borrower an affordable monthly payment while letting the lender reprice or reassess the credit at maturity. The borrower's job is to have a refinance or sale plan ready well before that balloon comes due.
What's the difference between interest-only and amortizing periods?
During an interest-only period, the entire payment covers interest and the principal balance does not decrease at all, versus an amortizing payment where a portion of every payment reduces the balance — meaning interest-only loans build zero equity through paydown and leave the full original balance due at the end of the interest-only period or at maturity. Many bridge and construction loans are fully interest-only for their entire term. Many permanent loans use a shorter interest-only period (one to three years) followed by a standard amortization schedule for the remainder of the term. Confirm which structure you're being quoted — it changes your cash flow and your payoff balance dramatically.
Sample amortization schedule: $2,000,000 loan, 6.5% rate, 25-year amortization
| Year | Beginning Balance | Annual Interest | Annual Principal | Ending Balance |
|---|---|---|---|---|
| 1 | $2,000,000 | $128,400 | $32,760 | $1,967,240 |
| 2 | $1,967,240 | $126,300 | $34,860 | $1,932,380 |
| 5 | $1,858,900 | $119,000 | $42,160 | $1,816,740 |
| 10 | $1,624,300 | $103,600 | $57,560 | $1,566,740 |
| 25 (fully amortized) | — | — | — | $0 |
Figures are illustrative and rounded; actual amortization depends on exact rate, payment frequency, and day-count convention. Use the free amortization schedule tool below to generate exact numbers for your own loan terms.
Notice how little of the balance moves in the first two years compared to year ten — this is the "front-loaded interest" effect that makes early-year prepayment far less valuable than borrowers often assume.
How do you calculate your own loan's amortization schedule?
You can calculate an amortization schedule manually with the standard mortgage-payment formula, but for anything beyond a rough estimate, use our free amortization schedule tool — enter your loan amount, rate, amortization period, and term, and it generates a full year-by-year (or month-by-month) breakdown of principal, interest, and remaining balance, including balloon payment sizing if your term is shorter than your amortization period. This is the fastest way to see exactly what balance you'll owe at any future point, which is essential for planning a refinance or evaluating a bridge loan's exit risk — see our piece on common bridge loan mistakes for how balloon payment surprises actually play out for borrowers.
Why does amortization period matter more than the interest rate for some borrowers?
Because a longer amortization period lowers your monthly payment and improves cash-on-cash returns during the hold, even at a slightly higher rate, and can matter more to a cash-flow-constrained borrower than shaving a few basis points off the rate. This is also directly connected to DSCR — since a lender calculates debt service using your amortizing payment, a longer amortization period lowers the annual debt service figure and can be the difference between clearing a 1.25x DSCR test and falling short of it. Our underwriting calculator lets you test both levers — rate and amortization period — against your DSCR target simultaneously.
The bottom line
Amortization determines not just your monthly payment but your entire payoff trajectory — how much equity you build through paydown, what balance remains at any point before maturity, and whether you face a balloon payment at the end of your term. Interest-only periods pause that paydown entirely. Before signing any commercial loan term sheet, run the actual numbers through an amortization schedule tool rather than comparing loans on monthly payment alone — the difference in your future payoff balance can be substantial even between two loans that look identical today.