Methodology

Formula Review & Open-Source Mathematics

We calculate debt yield, DSCR, LTV, cap rate, NOI, loan constant, payment, and maximum loan amount using transparent formulas shown on each calculator page. Inputs are validated for common data-entry errors before results are displayed.

To maintain strict academic reproducibility and institutional transparency, our underlying underwriting math is open-source. Financial analysts, students, and software engineers can audit, verify, or integrate our TypeScript and Python algorithms via the public repository at github.com/rizwantedx-dot/debt-yield-calculate.

For the full debt yield formula with worked examples, see how to calculate debt yield. For definitions of every metric, see the CRE finance glossary.

Underwriting Assumptions

• NOI is annual property income after operating expenses and before debt service.
• Replacement reserves are shown separately from operating NOI. Use the income definition required by the applicable lender for each test.
• DSCR uses annual debt service derived from rate and amortization.
• Amortizing payment examples use monthly payments and a nominal annual rate divided by 12. A zero-rate amortizing example repays principal evenly over the amortization period.
• LTV uses the value basis entered by the user, such as purchase price or appraisal.
• Debt yield divides annual NOI by loan amount and does not use rate or amortization.
• Maximum modeled loan amount is the lowest available result across the selected tests. Additional underwriting requirements can lower actual proceeds.
• Calculations retain precision internally; displayed currency and ratios are rounded. Small differences can result when recalculating from rounded displays.

Sources and Limits

Default targets and hypothetical examples are assumptions, not universal lender requirements. Confirm thresholds, income adjustments and interest-only treatment in the applicable quote or current program documents. Selecting a lender label does not verify eligibility. Results are not loan quotes, appraisals, tax advice, legal advice, or commitments to lend.

The agency underwriting guide links specific program sources. The CMBS guide separates a quoted floor from a hypothetical screen. For a reproducible example, use the loan-sizing walkthrough and its editable workbook.