Deal Analysis
Rental Property Comparison Calculator
Compare two or three rental properties side by side on cash flow, cap rate, cash-on-cash and more.
How to compare rental properties
When you compare rental properties side by side, the goal is to see how each deal stacks up on the metrics that actually drive your return. Price alone tells you almost nothing. A $250,000 home and a $300,000 home can produce very different cash flow depending on rent, expenses, and financing, so the only way to judge them is to lay the numbers out next to each other. Three metrics do most of the work. Monthly cash flow is rent minus vacancy, operating expenses, and the mortgage payment; it tells you whether the property puts money in your pocket each month or drains it. Cash-on-cash return compares that annual cash flow to the cash you invested (the down payment), so it answers how hard your money is working. Cap rate measures the property unlevered yield (net operating income divided by price) and lets you compare deals regardless of how they are financed. The gross rent multiplier (GRM) is a quick screen: price divided by annual gross rent. A common question is why a lower GRM is better. GRM is price relative to rent, so a smaller number means you are paying less for each dollar of income the property generates. A GRM of 8 is generally more attractive than a GRM of 12, all else being equal. GRM ignores expenses and financing, though, so treat it as a first filter rather than a verdict. This is also why the lowest price is not always the best deal. A cheaper home may come with lower rent, higher maintenance, or a tougher neighborhood that eats into cash flow. A slightly more expensive property with stronger rent and reasonable expenses can produce better monthly cash flow and a higher cash-on-cash return even though it costs more up front. The comparison table makes that visible at a glance: each row highlights the better value in teal, so you can see which property wins on each metric without a spreadsheet. No spreadsheet needed, no sign-up, everything computes in your browser.
Worked example
The tool loads with two sample properties. Property A is a $250,000 home with 25% down, a 7% rate on a 30-year loan, and $2,500 monthly rent. Property B costs $300,000 with the same financing terms and $2,900 monthly rent. Both carry 5% vacancy, $3,000 annual tax, $1,200 insurance, 8% maintenance, and 8% property management.
Property A produces a monthly mortgage payment of about $1,248 and operating expenses of roughly $670, leaving monthly cash flow near $283. Property B has a larger loan (about $1,498/mo) but the higher rent pushes monthly cash flow to roughly $332. Property B wins on monthly cash flow.
On cash-on-cash return, Property A invests $62,500 and returns about 5.4%, while Property B invests $75,000 and returns about 5.3%. Property A edges ahead on cash-on-cash because its lower price means less cash invested for a similar return. Cap rate is close for both (around 5.7%), and GRM is lower for Property A (8.3 versus 8.6), so A looks like the better price relative to rent. The verdict line summarizes this: Property B has more monthly cash flow, while Property A has the higher cash-on-cash return.
Frequently asked questions
How do I compare two rental properties?
Enter the same inputs for each property in its own column: purchase price, down payment, rate, term, rent, vacancy, taxes, insurance, maintenance, management, HOA, and other expenses. The comparison table updates instantly, showing cash flow, cash-on-cash return, cap rate, and GRM for each property side by side, with the better value in each row highlighted in teal.
Which metric matters most?
It depends on your goal. Monthly cash flow matters most if you need income now. Cash-on-cash return matters most if you want to compare how hard your invested cash is working across deals. Cap rate is best for comparing the property itself regardless of financing. GRM is a fast first screen. Most investors look at all four together, which is exactly what the comparison table shows.
Is a higher cap rate always better?
Not necessarily. A higher cap rate means more income relative to price, which is usually attractive, but it can also signal higher risk, a tougher neighborhood, or deferred maintenance. In high-appreciation markets investors often accept lower cap rates because they expect values to rise. Use cap rate to compare similar properties in the same market, not as a standalone verdict.
Do I need a spreadsheet?
No. The calculator handles every formula in your browser and lays the results out side by side. No spreadsheet needed, no sign-up, and nothing is sent to a server. You can even copy a comparison link that encodes all your inputs into the URL so you can reopen or share the exact comparison later.
Can I compare three properties?
Yes. The tool starts with two properties, but an Add a third property button lets you add a third column (the maximum). All three then appear in the comparison table with the same metrics and the same per-row winner highlighting.
More Deal Analysis tools
- Rental Property Calculator Analyze cash flow, cash-on-cash return, cap rate, and GRM for any rental property.
- Cap Rate Calculator Calculate net operating income and capitalization rate for any rental property.
- NOI Calculator (Net Operating Income) Calculate net operating income, operating expense ratio, and estimated property value.
- Cash-on-Cash Return Calculator Measure the annual return on the actual cash you put into a rental property deal.
- Rental Yield Calculator Calculate gross and net rental yield to compare income relative to property price.
- Gross Rent Multiplier Calculator Screen deals fast with the gross rent multiplier and implied price at a target GRM.
- 1% Rule Calculator Check whether a rental deal meets the 1% rule and see the rent needed to pass.
- ARV Calculator Estimate after-repair value and maximum allowable offer for a fix-and-flip or BRRRR deal.