Investment Property Calculator

What is an investment property calculator?

An investment property calculator is a tool that estimates monthly cash flow, cap rate, and cash-on-cash return from purchase price, financing, rent, and operating expenses. Enter those numbers — this page does not pull comps, talk to a lender, or close a deal.

This is an estimate from the numbers you enter — not investment, tax, or lending advice. Cap rate and cash-on-cash return are modeled from your inputs, not a quote.

Who Is This For?

• Investors evaluating whether a specific rental property deal meets their minimum return criteria — 8%+ cash-on-cash, 6%+ cap rate — before making an offer.
• Real estate agents running numbers for investor clients, comparing multiple properties side by side to identify the strongest deal.
• Anyone learning rental property investing who wants to understand how cap rate and cash-on-cash return actually work with real numbers plugged in.

Key Benefits

• Privacy. Tool inputs stay in the browser.
• Free to use now. No account, no paywall. Ads are not live yet.
• No account needed. Works instantly — analyze as many deals as you want.
• Calculates all three core metrics at once. Cash flow, cap rate, and cash-on-cash return in a single analysis — the three numbers every serious investor evaluates before committing to a deal.

Use our BRRRR Calculator to model a full buy-rehab-refinance cycle, or the House Hacking Calculator if you plan to live in one unit.

Common Investment Property Analysis Mistakes

• Using asking rent instead of actual market rent from comparable properties. Landlords often list optimistic rents. Pull actual leased comps from Zillow, Rentometer, or a local property manager to verify what the market will actually support.
• Underestimating vacancy — 8-10% is realistic for most markets, not 5%. A 5% vacancy assumption means the unit is empty less than 3 weeks per year. In reality, tenant turnover, cleaning, and re-leasing time routinely exceed that in most markets.
• Forgetting capital expenditure reserves (roof, HVAC, water heater) — budget 5-10% of gross rent. CapEx is not a monthly cost you feel — until the HVAC fails. Setting aside 5-10% of gross rent monthly means you won't need to come out of pocket when major systems need replacement.
• Ignoring property management costs even if self-managing — your time has a cost and you may not self-manage forever. Model 8-10% property management into every deal even if you plan to self-manage. If you eventually hire a manager, your cash flow won't collapse. If you don't, it's upside you keep.

The 1% rule (monthly rent should be at least 1% of purchase price) and 50% rule (expect 50% of gross rent goes to expenses) are widely used screening benchmarks in residential real estate investing. For broader market data, see National Association of Realtors — Research & Statistics.

Common Use Cases

An investor evaluates a $250,000 single-family rental. They enter the purchase price, 20% down payment, 7.5% interest rate, $1,800/month rent, and realistic expense percentages. The calculator shows $180/month cash flow, 6.2% cap rate, and 7.1% cash-on-cash return — just below their 8% minimum, prompting them to negotiate the price down or pass on the deal.

A real estate agent has an investor client considering the same property at two different financing structures — conventional vs. cash purchase. They run both scenarios to show how financing affects cash-on-cash return without affecting cap rate, helping the client decide which approach fits their strategy.

A new investor compares three markets: Midwest, Southeast, and a coastal city. They model an average-priced rental in each to compare cap rates and understand why investors in appreciation markets accept lower cash flow in exchange for equity growth over time.

Frequently Asked Questions