ROI Calculator

Reading the Results

Cash-on-cash return answers the question every investor should ask first: for every dollar I locked into this deal, how many cents come back to me each year? Because it uses your actual cash invested rather than the full purchase price, it captures the effect of leverage. Cap rate strips financing out entirely and describes the property’s raw earning power, which is useful for comparing deals across markets. NOI is the annual income after operating costs, and monthly cash flow is the number that determines whether the property supports itself or quietly drains your savings.

Every Return Metric, and When It Misleads

Each metric answers one narrow question. Problems start when a number is used to answer a question it was never designed for. Here is what each one measures and the most common way it fools people.

Net operating income (NOI)

NOI is effective rental income (rent actually collected after vacancy and credit loss, plus other income such as laundry or pet fees) minus operating expenses. It excludes mortgage payments, income taxes, depreciation and capital you spend on improvements. Where it misleads: sellers often quote NOI with no vacancy allowance, no management fee (because they self-manage) and no reserve for roofs or furnaces. A seller’s NOI is a claim to verify, not a fact. Rebuild it from the rent roll, the tax bill and an insurance quote in your own name.

Cap rate

Cap rate is NOI divided by price (or current value). It tells you what the property yields if bought with all cash, so it is the cleanest way to compare a duplex in one city with a triplex in another. Where it misleads: it ignores financing, so a 7% cap rate property can still lose money every month if your loan costs 7.5%. It is also only as good as the NOI behind it, and it says nothing about future rent growth or the condition of the building. A low-cap property in a growing area and a high-cap property in a shrinking one can produce opposite long-term results.

Cash flow

Cash flow is NOI minus debt service (principal and interest). It is the money left for you each month. Where it misleads: a month with no repairs is not a typical month. If you count cash flow as rent minus mortgage, taxes and insurance, you are counting the reserves you will need for the next water heater as profit. Monthly cash flow also excludes principal paydown, so it understates your total return on an amortizing loan.

Cash-on-cash return

Annual cash flow divided by total cash invested. Where it misleads: it is a first-year snapshot. It ignores appreciation, principal paydown and the sale, and it rises sharply as your cash in the deal falls, so a deal with very little money down can show a spectacular percentage on a very small and fragile dollar amount. It also becomes less meaningful over time, because your equity grows while the denominator stays fixed at your original cash.

Return on equity

Return on equity divides annual cash flow (or total return) by your current equity, not your original cash. It is the metric that tells you when a property has become a lazy asset. If you bought with $60,000 and now have $250,000 of equity earning $9,000 a year, your cash-on-cash looks fine at 15% but your return on equity is 3.6%. That gap is exactly the question our keep-or-sell calculator is built to answer.

Total return and IRR

Total return adds cash flow, principal paydown and appreciation. The internal rate of return (IRR) turns the whole stream of cash in and out, including the sale, into one annualized percentage that you can compare with other investments. Where it misleads: IRR is extremely sensitive to the assumed sale price and appreciation rate. Small changes in a guess five or ten years out swing the answer more than anything you know today. Always run it with zero appreciation as well.

DSCR and gross rent multiplier

The debt service coverage ratio (NOI divided by annual debt service) is a safety measure rather than a return measure; lenders commonly want to see it comfortably above 1.0. The gross rent multiplier (price divided by annual gross rent) is a quick screening ratio that ignores expenses entirely. Use it to discard listings fast, never to decide to buy. See the ROI formulas cheat sheet for every formula on one page.

How to Estimate Expenses Honestly

Almost every disappointing rental was bought with a good rent estimate and a bad expense estimate. Build expenses line by line from sources you can check, and include costs that do not show up every month:

• Property taxes: use the county assessor’s current bill, and check whether a sale triggers reassessment in your state. The seller’s tax bill may reflect a homestead exemption or an old assessment you will not keep.
• Insurance: get a landlord (dwelling fire) policy quote for your own name and address before you make an offer. Premiums vary widely by location and claims history.
• Vacancy and credit loss: budget for turnover even with a great tenant. Five to eight percent of gross rent is a common planning range; use local data from the rent estimator and recent listings to judge your market.
• Repairs and maintenance: ongoing fixes such as plumbing calls, appliance repairs and turnover paint. Older buildings need more.
• Capital expenditures: roofs, HVAC, water heaters, flooring and parking surfaces wear out on a schedule. Estimate each item’s remaining life and replacement cost, then divide to get a monthly reserve. This is the line most often left at zero.
• Management: include it even if you self-manage. Your time has a cost, and a property that only works without a manager will not work when you want to step back or sell it to a buyer who will hire one.
• Owner-paid utilities, HOA dues, lawn and snow, pest control, licensing and inspections: small lines that add up, especially on small multifamily.

The expense ratio calculator is a good cross-check: if your operating expenses come out at a small fraction of rent on an older property, something is missing. The property analysis worksheet gives you a printable line-by-line template.

A Full Worked Example

Hypothetical example. A single-family rental costs $220,000. You put 25% down ($55,000) and pay $7,000 in closing costs and minor make-ready, so your cash invested is $62,000. The $165,000 loan is a 30-year fixed at 6.75%, so principal and interest are $1,070.19 a month, or $12,842 a year. Market rent is $2,200 a month.

The metrics: cap rate is $14,542 / $220,000 = 6.6%. Cash flow is $1,699 a year, about $142 a month. Cash-on-cash is $1,699 / $62,000 = 2.7%. DSCR is $14,542 / $12,842 = 1.13. Operating expenses are 42% of effective income.

Now the version most people run: rent minus mortgage, taxes and insurance only. That is $2,200 - $1,070 - $250 - $125 = $755 a month, or $9,058 a year, which looks like a 14.6% cash-on-cash return. The difference between 14.6% and 2.7% is entirely vacancy, maintenance, capital reserves, management and small costs. None of them are optional over a holding period; they simply arrive unevenly.

To use the calculator for this deal, enter $220,000 as the purchase price, $62,000 as the down payment (cash invested), $2,200 as rent, and $2,058 as monthly expenses ($1,070 debt service plus $988 of monthly operating costs including vacancy). It will report roughly $142 of monthly cash flow and a 2.7% cash-on-cash return.

ROI Over Time: Equity Build-Up and Appreciation

A 2.7% cash-on-cash return looks weak, and in year one it is. But cash flow is only one of three sources of return. In the first year of this loan, about $1,758 of your payments goes to principal. If the property appreciates 3%, that adds $6,600 of value. Year-one total return is $1,699 + $1,758 + $6,600 = $10,057, or 16.2% of your $62,000. The catch: only $1,699 of that is cash.

Extend it to a five-year hold, assuming rent and operating expenses both grow 3% a year and the loan payment stays fixed:

• Cumulative cash flow rises each year as rent grows and the payment does not: about $12,992 over five years.
• The loan balance falls from $165,000 to about $154,895, so principal paydown adds $10,105 of equity.
• At 3% a year the property is worth about $255,040 in year five.
• Selling costs of 7% (commission, transfer taxes, closing) are about $17,853.
• Net sale proceeds before income tax: $255,040 - $154,895 - $17,853 = $82,293.

Total pre-tax profit is $12,992 + $82,293 - $62,000 = $33,285, and the annualized return (IRR) is about 9.5%. Now run the same deal with no appreciation and flat rents: cash flow stays at $1,699 a year, sale proceeds are $220,000 - $154,895 - $15,400 = $49,705, and the investment loses about $3,800 over five years, an IRR of roughly -1.3%. The deal only works if the market cooperates. That is the kind of insight a single cash-on-cash figure hides, and it is why you should test appreciation at zero before you buy.

Notice also that selling costs alone consumed more than five years of cash flow. Short holds rarely pay on small rentals, and the longer you hold, the more principal paydown and rent growth work in your favor. The trade-off is that your equity grows and your return on that equity tends to fall, which is the point at which keeping, selling, refinancing or exchanging becomes a real decision.

The After-Tax View

While you hold, rental income is reported on Schedule E, and depreciation usually shrinks the taxable amount. Under IRS Publication 527, residential rental buildings are depreciated over 27.5 years; land is never depreciated. In the example, if $40,000 of the price is land, the $180,000 building produces about $6,545 of depreciation in a full year (the first year is prorated by the month you place it in service). Year-one interest is about $11,084, so taxable rental income is roughly $14,542 - $11,084 - $6,545 = -$3,088: a paper loss even though the property produced positive cash flow.

Whether you can use that loss now depends on the passive activity rules. Publication 527 explains that if you actively participate, you may deduct up to $25,000 of rental losses against other income; the allowance phases out between $100,000 and $150,000 of modified adjusted gross income (different limits apply if you are married filing separately). Losses you cannot use carry forward to later years.

The sale is where the tax bill arrives. Depreciation reduces your basis, so it increases your gain. The part of the gain attributable to depreciation (unrecaptured section 1250 gain) is taxed at a maximum 25% rate, according to IRS Topic 409; the rest of a long-term gain is taxed at 0%, 15% or 20% depending on income. Higher earners may also owe the 3.8% net investment income tax once modified AGI exceeds $200,000 (single) or $250,000 (married filing jointly). Note that depreciation you were allowed to take reduces your basis even if you never claimed it.

To see the after-tax proceeds of selling versus keeping, including depreciation recapture, capital gains brackets and the NIIT, run your numbers through the keep-or-sell rental property calculator. If you are considering deferring the tax by buying another property, the 1031 exchange calculator and the tax strategy guide cover the next steps. This section is general information, not tax advice; tax rules change and your situation may differ, so confirm with a CPA.

Common Mistakes When Calculating ROI

• Leaving out vacancy, capital reserves or management, which can turn a weak deal into an apparent winner.
• Using the down payment alone as cash invested and ignoring closing costs and upfront repairs.
• Mixing levered and unlevered numbers: calculating cap rate after the mortgage, or comparing your cash-on-cash with someone else’s cap rate.
• Counting appreciation as income, then buying a property that loses money every month on the strength of it.
• Ignoring selling costs and taxes when estimating the return on a planned sale.
• Never recalculating. A property bought at 10% cash-on-cash years ago may now earn very little on the equity it holds.

Stress-Test Before You Commit

Run at least three versions of every deal: your expected case, rent 10% lower, and a year with a major repair. In the worked example, cutting rent to $2,000 reduces effective income by about $2,280 a year and turns the cash flow negative. If a deal only works in the expected case, you are speculating rather than investing. Related tools: break-even calculator, property investment analyzer, refinance calculator, and the guide how to calculate ROI on rental properties.