Free Real Estate Investment Calculator
& Commercial Deal Analyzer
Instantly underwrite residential rental properties, commercial retail, multifamily apartments, and BRRRR value-add projects. Calculate Net Operating Income (NOI), Capitalization Rate, Cash-on-Cash Return, Lender DSCR, and Levered IRR in seconds — without spreadsheets, paywalls, or accounts.
How Do You Calculate Real Estate Investment Returns?
Real estate underwriting requires separating unlevered operational performance (how the physical property generates income) from levered financial performance (how debt financing impacts investor dividend yield).
1. Net Operating Income (NOI) Formula
Operating expenses include property taxes, insurance, repairs, vacancy reserves, and management. Mortgage payments are excluded.
2. Cash-on-Cash Return Formula
Total cash invested includes purchase down payment, loan closing points, escrow fees, and upfront renovation costs.
Real-World Case Study: $350,000 Single-Family Rental
Underwriting breakdown for a single-family turnkey rental purchased for $350,000 with a 20% down conventional loan at 6.50% interest:
- Purchase Price & Loan: $350,000 Price | $70,000 Down (20%) | $280,000 Loan @ 6.50% ($1,770/mo P&I)
- Gross Monthly Rental Income: $2,800 / month ($33,600 / year)
- Monthly Operating Expenses: $547 / month (Taxes $250, Insurance $95, Maintenance 5%, Management 8%)
- Net Operating Income (NOI): $27,036 / year ($2,253 / month)
- Net Monthly Cash Flow: +$483 / month net ($5,796 / year)
- Cash-on-Cash Return: 8.28% Cash-on-Cash ($5,796 cash flow ÷ $70,000 equity invested)
Who Uses DealAnalyzer?
Buy & Hold Investors
Model monthly cash flows, principal amortization, and long-term appreciation across residential and multifamily assets.
Commercial Real Estate Brokers
Underwrite retail, office, and industrial proformas with cap rates, DSCR, and institutional DCF models.
Wholesalers & Flippers
Calculate maximum allowable offers (MAO), 70% rule rehab buffers, and BRRRR exit refinance proceeds.
Top 5 Mistakes to Avoid in Real Estate Underwriting
1. Underestimating Capital Expenditures (CapEx): Routine repairs cover small fixes; CapEx covers roofs, HVAC, and structural assets. Always reserve 5% to 8% of rent.
2. Assuming Zero Vacancy: Tenant turnover, cleaning, and marketing create vacancy downtime. Model at least 5% to 8% vacancy.
3. Ignoring Post-Sale Property Tax Reassessments: Purchase transactions trigger property tax reassessments based on the new acquisition price.
4. Confusing Pro Forma Cap Rates with In-Place Cap Rates: Always underwrite using verified Trailing-12 financial statements rather than broker marketing proformas.
5. Storing Deal Data in Central Cloud Servers: Protecting sensitive off-market pricing and proprietary underwriting requires local in-browser calculation tools.
Frequently Asked Questions About Deal Analysis
How is rental property cash flow calculated?
Rental property cash flow is calculated by subtracting operating expenses and mortgage debt service from gross rental revenue.
What is the difference between Cap Rate and Cash-on-Cash Return?
Cap Rate evaluates unlevered property yield on total price. Cash-on-Cash Return measures the dividend yield on your actual out-of-pocket down payment after paying loan debt service.
Why avoid manual Excel spreadsheets?
Manual spreadsheets are prone to silent formula breaks, cannot be easily adjusted during mobile walkthroughs, and lack automated validation.
Is DealAnalyzer 100% free with no login?
Yes. DealAnalyzer is 100% free forever, has no calculation caps, and runs entirely in your local browser.
What is a good Debt Service Coverage Ratio (DSCR)?
Most lenders require a minimum DSCR of 1.20x to 1.25x to ensure net operating income comfortably exceeds annual mortgage payments.