Commercial Real Estate Loan Calculator
Calculate commercial mortgage payments, balloon payment at maturity, interest-only options, and loan balance with instant Excel schedule export.
Interactive WebAssembly Calculation Engine
This tool runs 100% in your local web browser tab. All amortization schedules, debt yield calculations, and tax deferral projections are computed client-side in WebAssembly. Zero bytes are uploaded to remote servers.
Use the interactive form above to adjust parameters, toggle extra principal schedules, stress-test interest rates, and export full reports to Excel (.xlsx) or CSV.
Underwriting Methodology & Mathematical Formulation
Our calculation algorithms strictly adhere to institutional lending conventions, CFPB disclosure rules, and statutory IRS definitions:
- Standard Annuity Formula: Monthly payment M = P * [r(1+r)^n] / [(1+r)^n - 1], calculating exact interest and principal allocations down to the penny.
- Zero-Roundoff Double Precision: Computations execute using standard IEEE 754 floating-point and integer math to match commercial bank loan documents.
- Sensitivity Analysis: Real-time stress testing against interest rate fluctuations, vacancy rate increases, and balloon maturity horizons.
Frequently Asked Questions
What is a balloon payment on a commercial real estate loan?
A balloon payment is the remaining lump-sum principal balance due at the end of a commercial loan term (often 5, 7, or 10 years) when the amortization schedule is longer (typically 20, 25, or 30 years). The borrower must pay off, refinance, or sell the property before the balloon maturity date.
Why do commercial mortgages have 20 or 25-year amortizations with 5 or 10-year terms?
Commercial lenders avoid locking in long-term fixed interest rates for 30 years due to interest rate risk. Structuring loans with a 25-year amortization keeps monthly debt service manageable while a 5-to-10-year maturity allows the bank to re-evaluate underwriting and reset interest rates.
What happens when a commercial balloon loan matures?
Upon maturity, the borrower must satisfy the balloon payment by refinancing with the current lender or a new lender, paying cash from reserves, or selling the asset. Borrowers should begin the refinancing process 6 to 12 months prior to the balloon maturity date.
What is an Interest-Only (IO) period in commercial financing?
During an Interest-Only period (e.g. initial 1 to 3 years), the borrower only pays monthly interest and no principal. This maximizes cash flow during property renovations, tenant lease-up, or stabilization before standard amortization commences.