Rental Property Calculator

Evaluate any rental property investment in seconds. Calculate monthly cash flow, cap rate, cash-on-cash return, and long-term ROI — completely free.

How to Use This Calculator

1Enter the purchase price, down payment, and loan terms for the property you’re evaluating.
2Add operating expenses — property tax, insurance, maintenance, and any HOA fees.
3Input expected monthly rent and set vacancy and management rates for your market.
4Review your results instantly. Adjust any number to model different scenarios.
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Monthly Cash Flow

STRONG
+$327
per month
1% rule
DSCR 1.32x
MortgageExpensesCash Flow
Effective Rent$1,805
Mortgage (P&I)$1,011
Operating Expenses$467
=Net Cash Flow+$327

Annual Returns · Year 1

Cap Rate
8.0%
0%12%+
Cash-on-Cash
9.8%
-5%20%+
NOI
$16,060
Cash Flow
+$3,924
Cash In
$40,000
Loan
$160,000
Debt/Yr
$12,136

How to Evaluate a Rental Property

Evaluating a rental property comes down to three questions: Does it cash flow? What’s the return on my money? And will it appreciate over time? This calculator answers all three.

Monthly cash flow is the simplest metric — it’s what’s left after you pay the mortgage, taxes, insurance, and all operating expenses. Positive cash flow means the property pays for itself from day one. Negative cash flow means you’re subsidizing the investment out of pocket, betting on appreciation.

Cap rate (capitalization rate) measures the property’s income potential independent of financing. It’s calculated as Net Operating Income divided by the purchase price. This lets you compare properties apples-to-apples regardless of how they’re financed.

Cash-on-cash return tells you how hard your actual cash investment is working. It divides your annual cash flow by the total cash you put in (down payment + closing costs + repairs). A property with 20% down has a very different cash-on-cash than one with 5% down, even if the cap rate is identical.

Internal Rate of Return (IRR) captures the complete picture. It accounts for the timing of every dollar — your initial investment, each year’s cash flow, and the proceeds when you sell. IRR is the single best metric for comparing rental property investments to stocks, bonds, or other alternatives.

Quick Rules of Thumb

Before running full numbers, experienced investors use these screening rules to quickly filter properties. None are perfect alone — always run the complete analysis above.

1% Rule

Monthly rent ≥ 1% of purchase price

$200,000 property → $2,000/mo rent

Quick screening filter. Properties passing 1% tend to cash flow well. Below 0.8% rarely works with conventional financing.

50% Rule

50% of rent goes to non-mortgage expenses

$2,000/mo rent → $1,000/mo expenses

Includes taxes, insurance, maintenance, vacancy, and management. Use this for back-of-envelope analysis before running full numbers.

DSCR ≥ 1.25

NOI should be 1.25× annual debt service

$12,000 NOI ÷ $9,600 debt = 1.25x

Debt Service Coverage Ratio. Lenders require 1.2–1.25x minimum. Higher DSCR means more cushion if income drops or expenses spike.

Understanding Your Results

Monthly Cash Flow

Rent collected minus mortgage, taxes, insurance, maintenance, and all other expenses.

Target

Any positive number means the property pays for itself. $100–$200/door/month is a common target for buy-and-hold investors.

Watch Out

Negative cash flow means you’re subsidizing the investment. This can work if appreciation is strong, but it’s risky for first-time investors.

Cap Rate

Net Operating Income divided by purchase price. Measures the property’s income potential without financing.

Target

4–6% in major metros, 6–10% in secondary markets. Higher cap rate = higher income relative to price, but often higher risk.

Watch Out

Cap rate ignores financing. Two investors buying the same property at the same cap rate will have very different returns if one puts 5% down and the other puts 50% down.

Cash-on-Cash Return

Annual cash flow divided by total cash invested (down payment + closing costs + repairs).

Target

8–12% is a strong cash-on-cash. Above 12% is excellent. This is the best measure of how hard your actual dollars are working.

Watch Out

Leverage amplifies cash-on-cash in both directions. Low down payment boosts returns when things go well, but magnifies losses when they don’t.

IRR (Internal Rate of Return)

The annualized return accounting for the timing of all cash flows — investment, yearly cash flow, and sale.

Target

10–15% is strong for rental properties. Above 15% is excellent. Compare to S&P 500 historical average of ~10% to benchmark.

Watch Out

IRR is sensitive to holding period and exit assumptions. Always stress-test by adjusting appreciation rate and selling costs.

Key Formulas Explained

Cap Rate

NOI ÷ Purchase Price

$12,000 NOI ÷ $200,000 = 6.0%

Cash-on-Cash Return

Annual Cash Flow ÷ Total Cash Invested

$3,600 ÷ $45,000 = 8.0%

NOI

Effective Income − Operating Expenses

Excludes mortgage — only property-level income and costs

IRR

Discount rate where NPV of all cash flows = 0

Accounts for timing of investment, cash flows, and sale

DSCR

NOI ÷ Annual Debt Service

$12,000 NOI ÷ $9,600 debt = 1.25x

Monthly Mortgage

P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1]

P = loan amount, r = monthly rate, n = total payments

Tips for First-Time Rental Investors

Run conservative numbers. Use a higher vacancy rate (8–10%), lower rent estimates, and higher maintenance budgets than you think you’ll need. If the deal still works with pessimistic assumptions, it’ll work in practice.

Don’t ignore management costs. Even if you self-manage, budget 8–10% for management. Either you’ll eventually hire a manager, or your time has value. This calculator defaults to 0% for self-managing landlords, but adjust it to see the true picture.

Cash flow is king for small portfolios. Appreciation is a bonus, not a strategy. Focus on properties that cash flow positive from month one. You can’t predict appreciation, but you can calculate cash flow.

Stress-test your assumptions. What happens if rent drops 10%? If vacancy doubles? If you need a $5,000 repair in year two? Use this calculator to model worst-case scenarios. A deal that only works under perfect conditions isn’t a deal.

Look at the full picture, not just cash flow. A property with modest cash flow but strong equity buildup and appreciation can outperform a high-cash-flow property in a declining market. IRR captures this — compare it to what you’d earn in index funds.

Track everything once you buy. The difference between a good investment and a great one is knowing your actual numbers — not projections. Tools like Vantric help small landlords track rent, expenses, and maintenance in one place so you always know where you stand.

Common Mistakes When Analyzing Rental Properties

Underestimating expenses. New investors routinely forget about vacancy, maintenance reserves, property management, capital expenditures, and rising property taxes. The 50% rule exists for a reason — non-mortgage expenses often consume half of gross rent.

Using asking rent instead of market rent. Zillow estimates and landlord wishful thinking inflate returns on paper. Check actual comparable rents on Rentometer, Zillow Rental Manager, or local listings. Be honest about what the market will bear.

Ignoring closing costs and repairs. These increase your total cash invested, which directly lowers cash-on-cash return. A property that looks like an 8% cash-on-cash deal becomes 6% after you factor in $8,000 in closing costs and $12,000 in deferred maintenance.

Over-relying on appreciation. Betting on 5%+ annual appreciation to make a deal work is speculation, not investing. Conservative investors assume 2–3% appreciation (roughly inflation) and treat anything above that as a bonus.

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Frequently Asked Questions