Free rental property calculator
Rental Property Calculator
Estimate cash flow, cap rate, and returns for any rental property. Built for investors who want accurate numbers — not just optimistic projections.
Sample calculation
A $300,000 duplex with $2,800/month gross rent, 25% down at 6.5%, with standard expense assumptions:
Gross rent
$2,800/mo
Total across both units
Operating expenses
$1,245/mo
Vacancy, mgmt, maintenance, taxes, insurance
Mortgage payment
$1,185/mo
25% down, 6.5%, 30 yr
Monthly cash flow
$370/mo
Net after all expenses
Cap rate
6.6%
NOI / purchase price
Cash-on-cash
6.1%
Annual cash / equity invested
What the calculator includes
- Gross rental income — Monthly rent times 12, adjusted for vacancy allowance.
- Operating expenses — Property management, maintenance, CapEx reserve, taxes, and insurance.
- Net operating income (NOI) — Income minus operating expenses, before debt service.
- Mortgage payment — Principal and interest based on your financing terms.
- Cash flow — NOI minus mortgage payment, on a monthly and annual basis.
- Return metrics — Cap rate, cash-on-cash return, gross yield, and DSCR.
Why not use a spreadsheet?
Spreadsheets require you to build and maintain formulas, catch formula errors, and manually update assumptions. DealPrism handles all of that — plus it surfaces risk signals automatically, like when your DSCR drops below 1.0 or your expense ratio exceeds market norms.
Frequently asked questions
- How do I calculate rental property cash flow?
- Cash flow equals gross rent minus all operating expenses (vacancy, management, maintenance, CapEx, taxes, insurance) minus your mortgage payment. DealPrism calculates this automatically from your inputs.
- What expenses should I include in a rental property analysis?
- Include vacancy allowance (typically 5–10%), property management (8–12%), maintenance (1–2% of property value), capital expenditure reserve (1–2%), property taxes, and landlord insurance. Skipping any of these overstates returns.
- What is a good cap rate for a rental property?
- Cap rates vary by market. High-growth metros like Austin or Denver often see cap rates of 3–5%. Midwest markets like Cleveland or Indianapolis may see 7–9%. Higher cap rates typically mean higher cash flow but slower appreciation.
- How much down payment do I need for a rental property?
- Most conventional investment property loans require 15–25% down. FHA loans (for owner-occupied multi-family) can require as little as 3.5%. The down payment affects your cash-on-cash return significantly.
- What is the 1% rule for rental properties?
- The 1% rule says monthly rent should be at least 1% of the purchase price. For example, a $200,000 property should rent for $2,000/month. It is a quick filter, not a substitute for full analysis — use DealPrism to calculate actual returns.
- Can I use this calculator for multi-family properties?
- Yes. Enter total gross rent across all units and adjust vacancy and maintenance percentages to reflect multi-unit risk. DealPrism handles any property type that generates rental income.
Run your rental property numbers
Free to use. No account required to see results. Save your analysis when you are ready to revisit the assumptions.
Analyze your own deal — freeResults are based on user-entered assumptions. Values may vary by property, location, and market conditions. Review all assumptions before making investment decisions.