How Commercial RE Underwriting Tool Works
The Commercial RE Underwriting tool helps real estate investors and analysts evaluate commercial property acquisitions by calculating the key financial metrics lenders and equity investors use to make decisions. Input your property's income, expenses, purchase price, and loan terms to get an instant underwriting summary.
The tool starts by computing Net Operating Income (NOI) — the property's gross income minus operating expenses, excluding debt service. NOI is the foundation of commercial real estate valuation and drives both the cap rate and debt coverage calculations. The capitalization rate (cap rate) expresses NOI as a percentage of property value, giving you a standardized return metric to compare across properties and markets.
Debt Service Coverage Ratio (DSCR) is critical for loan qualification. Lenders typically require a DSCR of 1.20x to 1.35x, meaning the property generates 20-35% more income than needed to cover mortgage payments. The tool calculates your DSCR based on your loan amount, interest rate, and amortization schedule, flagging if you fall below common lending thresholds.
Beyond these core metrics, the tool provides cash-on-cash return (annual pre-tax cash flow divided by total cash invested), internal rate of return projections, and a pro forma that models rent growth and expense escalation over your hold period. This comprehensive analysis gives you the same underwriting framework used by institutional investors and can be paired with the Cost Segregation Study Estimator to model tax-advantaged returns.
Key Terms Explained
- Net Operating Income (NOI)
- A property's total income minus operating expenses, excluding debt service and capital expenditures.
- Cap Rate
- The ratio of NOI to property value, used to estimate the return on a commercial real estate investment.
- DSCR (Debt Service Coverage Ratio)
- The ratio of NOI to annual debt payments, measuring a property's ability to cover its mortgage obligations.
- Cash-on-Cash Return
- The annual pre-tax cash flow divided by total equity invested, showing the yield on your actual cash outlay.
- Loan-to-Value (LTV)
- The ratio of the mortgage amount to the property's appraised value, used by lenders to assess risk.
- Pro Forma
- A forward-looking financial projection of a property's income, expenses, and returns over a specified hold period.
Who Needs This Tool
Quickly evaluating whether a listed property meets minimum return thresholds before spending time on full due diligence.
Pre-qualifying a borrower's property by checking DSCR and LTV against various lender programs.
Building an investor pitch showing projected cash-on-cash returns and IRR for a multifamily acquisition.
Demonstrating to an owner how rent increases would affect NOI and overall property valuation.
Comparing multiple acquisition targets side-by-side using standardized underwriting metrics.
Methodology & Formulas
NOI = Gross Potential Rent - Vacancy Allowance - Operating Expenses. Cap Rate = NOI / Property Value × 100. DSCR = NOI / Annual Debt Service. Annual Debt Service uses standard amortization: Payment = Principal × [r(1+r)^n] / [(1+r)^n - 1] where r is the periodic rate and n is total payments. Cash-on-Cash Return = Annual Pre-Tax Cash Flow / Total Cash Invested × 100. Loan-to-Value (LTV) = Loan Amount / Property Value × 100.
Pro Tips
- Always use a realistic vacancy rate (5-10% for stabilized properties) rather than assuming 100% occupancy — lenders will discount your numbers if you don't.
- Include a reserve for capital expenditures (typically 5-10% of gross income) even if the property seems well-maintained.
- Compare your assumed cap rate to recent comparable sales in the market — an unrealistic exit cap rate can make any deal look attractive.
- Model a stress scenario with interest rates 1-2% higher to ensure the deal still works if rates rise during your hold period.
- Remember that DSCR requirements vary by property type — retail and office may require higher coverage than multifamily.