Commercial Loan Calculator
Calculate the payment on a commercial real estate or business term loan with separate amortization and maturity, the balloon due, and interest before it.
Interactive calculator · Method COMMERCIAL-LOAN-1.0 · Last reviewed: 2026-11-04
Calculate your scenario
Periodic rate r = annual rate ÷ 100 ÷ payments per year; n = amortization years × payments per year.
Your inputs
Default worked example. Edit the inputs to calculate your scenario.
Default worked example
Payment = $1,000,000.00 amortized over 300 payments at 7% ÷ 12 = $7,067.79; after 120 payments the balloon due is $786,333.96.
How to use the calculator
Enter the principal, rate, the amortization period that sets the payment, the maturity when the remaining balance is due, and whether payments are monthly or quarterly.
What the result means
A $1,000,000 loan at 7% amortized over 25 years costs $7,067.79 a month; after 10 years $786,333.96 is still owed as a balloon.
Formula and units
Periodic rate r = annual rate ÷ 100 ÷ payments per year; n = amortization years × payments per year. Payment M = P × r ÷ (1 − (1 + r)^−n), or P ÷ n at 0%. After k = maturity years × payments per year payments, the balloon is B = P(1 + r)^k − M((1 + r)^k − 1) ÷ r. Total payments before balloon = M × k; interest = M × k − (P − B). Interest-only alternative = P × r per period.
Worked examples
$1,000,000 at 7%, 25-year amortization, 10-year balloon: Loan principal: 1000000 USD; Annual interest rate: 7 %; Amortization period: 25 years; Maturity (balloon) term: 10 years; Payments per year: 12.
Example result: Periodic payment: $7,067.79 per month; Balloon balance due at maturity: $786,333.96 after 120 payments; Total payments before balloon: $848,135.04; Interest before balloon: $634,469.00; Principal repaid before balloon: $213,666.04; Interest-only payment alternative: $5,833.33 per month.
$250,000 term loan at 9%, quarterly, 10-year amortization, 5-year maturity: Loan principal: 250000 USD; Annual interest rate: 9 %; Amortization period: 10 years; Maturity (balloon) term: 5 years; Payments per year: 4.
Example result: Periodic payment: $9,544.34 per quarter; Balloon balance due at maturity: $152,363.17 after 20 payments; Total payments before balloon: $190,886.89; Interest before balloon: $93,250.06; Principal repaid before balloon: $97,636.83; Interest-only payment alternative: $5,625.00 per quarter.
Limitations and common mistakes
Fixed rate, level payments and interest compounded at the payment frequency. It leaves out origination fees, prepayment penalties or yield maintenance, actual/360 day-count interest, rate resets, reserves and any lender-specific or program terms such as SBA rules; it says nothing about qualifying for a loan. Rates are figures you enter; the defaults are only examples.
Assuming a 25-year amortization means the loan lasts 25 years. With a 10-year maturity, most of the principal is still due as a balloon at year 10.
Sources and assumptions
Method COMMERCIAL-LOAN-1.0; last formula review 2026-11-04. Sources and their supported claims. Calculation methodology.