Rental Cash Flow Calculator (USA)
Analyze any rental property in seconds. See your monthly and annual cash flow, cash-on-cash return, cap rate, NOI, DSCR, and a full multi-year projection — all in one place.
| Yr | Gross income | Op. expenses | NOI | Debt service | Cash flow | Cumulative |
|---|---|---|---|---|---|---|
| Calculate to see projection | ||||||
How to use the rental cash flow calculator
Four steps take a listing from asking price to a verdict — what the property earns each month, what it returns on the cash you put in, and whether it covers its own loan.
Price the purchase
Purchase price, down payment, closing costs, and any repairs before the first tenant.
Enter the income
Market rent, any other income, and a vacancy rate — the property will not be full every month.
Load every expense
Tax, insurance, management, and reserves for maintenance and capital items.
Read the returns
Cash flow, cash-on-cash, cap rate, DSCR, a multi-year projection, and a downloadable PDF.
The expenses you leave out are the ones that decide the deal. Vacancy, maintenance, and capital reserves cost nothing in a good year and thousands in a bad one. Strip all three out of the default example and cash flow jumps from about 186 a month to 637 — the same property, three and a half times the apparent return, and none of it real. A deal that only works with the reserves removed does not work.
How rental cash flow is calculated
Every metric on this page descends from one chain: income becomes effective income, effective income becomes net operating income, and net operating income becomes cash flow once the lender is paid. Each step answers a different question about the deal.
Worked example — 300,000 property, 25% down at 6.75%, renting for 2,650 a month
Effective gross income: 2,650 − 132.50 vacancy = 2,517.50
Operating expenses: 290 tax + 105 insurance + 212 management + 132.50 maintenance + 132.50 CapEx = 872
Net operating income: 2,517.50 − 872 = 1,645.50 a month
Debt service on the 225,000 loan: 1,459.35 a month
≈ 186 a month in cash flow — 2,234 a year on 80,000 invested, a 2.79% cash-on-cash return against a 6.58% cap rate.
Rental cash flow charts
Lookups for the levers that actually move a deal — where the rent goes, what financing does to the return, and how little rent it takes to tip the whole thing negative. Figures use the 300,000 example at 25% down, 6.75%, renting for 2,650, unless noted.
| Component | Per month | Per year | % of gross rent |
|---|---|---|---|
| Mortgage P&I | 1,459.35 | 17,512 | 55.1% |
| Property tax | 290.00 | 3,480 | 10.9% |
| Management (8%) | 212.00 | 2,544 | 8.0% |
| Maintenance (5%) | 132.50 | 1,590 | 5.0% |
| CapEx reserve (5%) | 132.50 | 1,590 | 5.0% |
| Vacancy (5%) | 132.50 | 1,590 | 5.0% |
| Insurance | 105.00 | 1,260 | 4.0% |
| Cash flow | 186.15 | 2,234 | 7.0% |
Seven cents of every rent dollar reaches you. That is normal for a leveraged rental at current rates — and it is why a single wrong assumption on tax or insurance can erase the entire return.
| Down payment | Monthly P&I | Monthly cash flow | Cash invested | Cash-on-cash | DSCR |
|---|---|---|---|---|---|
| 20% (60,000) | 1,556.64 | 88.86 | 65,000 | 1.64% | 1.06 |
| 25% (75,000) | 1,459.35 | 186.15 | 80,000 | 2.79% | 1.13 |
| 30% (90,000) | 1,362.06 | 283.44 | 95,000 | 3.58% | 1.21 |
| 40% (120,000) | 1,167.48 | 478.02 | 125,000 | 4.59% | 1.41 |
| All cash | 0.00 | 1,645.50 | 305,000 | 6.47% | — |
Note which direction the return moves. Because the 6.75% mortgage costs more than the property’s 6.58% cap rate, every extra dollar borrowed lowers the cash-on-cash return — negative leverage. When the cap rate sits above the loan rate the table inverts and borrowing amplifies the return instead.
| Rate on the 225,000 loan | Monthly P&I | Monthly cash flow | Annual cash flow | Cash-on-cash | DSCR |
|---|---|---|---|---|---|
| 5.50% | 1,277.53 | 367.97 | 4,416 | 5.52% | 1.29 |
| 6.00% | 1,348.99 | 296.51 | 3,558 | 4.45% | 1.22 |
| 6.75% | 1,459.35 | 186.15 | 2,234 | 2.79% | 1.13 |
| 7.50% | 1,573.23 | 72.27 | 867 | 1.08% | 1.05 |
| 8.00% | 1,650.97 | −5.47 | −66 | −0.08% | 1.00 |
Two points of rate is the difference between a 5.5% return and a loss. This is the single most sensitive input in the model, which is why a rate quote — not a rate guess — belongs in the calculator before you make an offer.
| Monthly rent | Monthly cash flow | Annual cash flow | Cash-on-cash | Cap rate |
|---|---|---|---|---|
| 2,400 | −6.35 | −76 | −0.10% | 5.81% |
| 2,500 | 70.65 | 848 | 1.06% | 6.12% |
| 2,650 | 186.15 | 2,234 | 2.79% | 6.58% |
| 2,800 | 301.65 | 3,620 | 4.52% | 7.04% |
| 3,000 | 455.65 | 5,468 | 6.83% | 7.66% |
Breakeven rent on this deal is about 2,408 — roughly 9% below the assumed 2,650. That gap is your entire margin for a soft rental market, so verify the rent against signed comparable leases rather than listing prices, which are asks rather than results.
| Year | Gross income | Operating expenses | NOI | Annual cash flow | Cumulative |
|---|---|---|---|---|---|
| 1 | 31,800 | 10,464 | 19,746 | 2,234 | 2,234 |
| 5 | 34,421 | 11,428 | 21,272 | 3,760 | 14,950 |
| 10 | 38,003 | 12,691 | 23,345 | 5,832 | 39,890 |
| 15 | 41,959 | 14,148 | 25,611 | 8,099 | 75,771 |
| 20 | 46,327 | 15,833 | 28,094 | 10,582 | 123,617 |
| 25 | 51,148 | 17,784 | 30,811 | 13,299 | 184,570 |
| 30 | 56,472 | 20,041 | 33,783 | 16,271 | 259,874 |
The mortgage payment never changes while rent rises, so cash flow compounds even at modest growth. Cumulative cash flow repays the 80,000 invested at around year 16 — and that is before the loan payoff and before appreciation, which at 3% a year would put the property near 728,000 by year 30.
NOI ÷ price
cash flow ÷ cash in
NOI ÷ debt service
Three metrics, three different questions. They disagree on purpose, and a deal that looks good on one can fail badly on another — so read all three before deciding what you are looking at.
- Cap rate — is this property priced well for its market, regardless of how anyone finances it?
- Cash-on-cash — is my capital better used here than anywhere else available to me?
- DSCR — does the property cover its own loan, or do I cover it in the thin months?
Everything the calculator works out
One property, fully modelled — the operating picture, the financing, the return metrics, and three decades of projection in a single pass.
Key figures behind the example deal
Built for the offer you haven’t made yet
The point of running numbers is to walk away from the wrong deal cheaply. These are the people who use the calculator before they commit.
Comparing listings and trying to work out whether a property that looks affordable will actually pay for itself once every real cost is loaded in.
- Never model zero vacancy or zero repairs
- Check whether tax reassesses after sale
- Keep reserves outside the deal, in cash
Financing on the property’s income rather than personal income, and needs to know the coverage ratio before the lender runs it.
- Target the lender’s stated DSCR floor
- Ask whether taxes and insurance count in their ratio
- More down payment lifts DSCR directly
Screening several properties at once and needs a consistent basis — same assumptions, same reserves — to rank them honestly.
- Use identical vacancy and reserve rates across deals
- Compare cap rate before financing distorts it
- Export each PDF and line them up
7 tips for analyzing rental cash flow
Most bad rental purchases are not bad properties — they are good properties bought on optimistic inputs. These are the inputs worth being hard-nosed about.
Rental cash flow calculator FAQ
The cash flow, return, ratio, and expense questions investors ask most.
Cash flow is what is left after every dollar the property collects has paid every dollar it costs. Start with rent and other income, subtract vacancy to get effective gross income, subtract operating expenses to get net operating income, then subtract the mortgage payment.
On a 300,000 property renting for 2,650 with 25% down at 6.75%, that runs 2,650 rent, minus 132.50 vacancy, minus 872 in operating expenses, minus 1,459.35 of principal and interest — leaving about 186 a month, or roughly 2,234 a year.
There is no universal figure, and the popular targets of 100 or 200 per door are rules of thumb rather than standards. What matters is whether the cash flow is large enough to absorb a bad month without you funding it personally.
A 186 a month cushion sounds positive but covers roughly one water heater a year. Judge the number against the size of a realistic surprise — a turnover, a furnace, two months vacant — and against the return on the cash you tied up, not against a round number someone quoted online.
Cash-on-cash return is annual cash flow divided by the total cash you put in — down payment, closing costs, and any upfront repairs. In the example that is 2,234 divided by 80,000, or about 2.79%.
Investors commonly look for 6% to 10%, but the honest comparison is against what that cash would earn elsewhere at similar risk. Cash flow is only one of four returns a rental produces; principal paydown, appreciation, and tax treatment are not captured in this figure.
Cap rate ignores your loan entirely: net operating income divided by the purchase price. It describes the property. Cash-on-cash includes the loan and describes your position in it.
The example property has a 6.58% cap rate but only a 2.79% cash-on-cash return, because the mortgage costs 6.75% — more than the property yields. When the mortgage rate is above the cap rate, borrowing reduces your return rather than amplifying it, which is why the all-cash version of the same deal returns about 6.47%.
Debt service coverage ratio is net operating income divided by the mortgage payment. It answers one question: does the property cover its own loan? At 1,645.50 of monthly NOI against a 1,459.35 payment, the example scores about 1.13.
Investment property lenders frequently want 1.20 to 1.25 or better, and DSCR loan programs qualify the property on this ratio rather than your personal income. Below 1.0 the property does not cover its debt and the shortfall comes from you.
The ones that do not arrive as a monthly bill. Vacancy, maintenance, and capital reserves for the roof, HVAC, and water heater cost nothing in a good year and thousands in a bad one, so they get left out of the spreadsheet.
Property tax is the other common miss: many counties reassess after a sale, so the seller’s tax bill can understate yours significantly. Verify the reassessment rules for the county, get a landlord insurance quote rather than assuming a homeowner rate, and price management even if you plan to self-manage.
It is a screening shortcut, not an analysis. The rule asks whether monthly rent is at least 1% of the purchase price; the example property comes in at 0.88%, so it fails.
The rule was built when interest rates and insurance costs were far lower, and it says nothing about taxes, insurance, HOA dues, or your rate. Use it to decide which listings deserve a closer look, then run the actual numbers — plenty of properties clear 1% and lose money, and some below it perform well.
Sometimes, but only as a deliberate choice with the shortfall funded from reserves you already hold. Investors accept it for strong appreciation markets, a below-market rent that can be raised, or a property being repositioned.
The risk is that negative cash flow removes your margin for error. A vacancy or a major repair then lands directly on your own finances, and you cannot wait out a soft market. If you are relying on rent growth or a refinance to fix the number later, both depend on conditions outside your control.
General Estimating Notice: This calculator models a rental property using the purchase, income, expense, financing, and growth figures you enter. It assumes a fixed-rate, fully-amortizing loan, steady annual growth rates, and expenses that behave as entered. It excludes income tax, depreciation and other tax treatment, mortgage insurance, leasing and turnover costs, eviction and legal costs, capital improvements beyond the reserve entered, selling costs, and any second lien. Projections are illustrations, not forecasts — rent growth, expense growth, vacancy, and appreciation are assumptions, and actual results depend on the market, the tenant, the condition of the property, and events no model anticipates. Cap rate, cash-on-cash return, and DSCR are calculated from your inputs; a lender may compute DSCR differently. Figures are not an offer, a quote, or financial, investment, tax, or legal advice. Verify rents, taxes, and insurance independently and consult a licensed professional before investing. For planning purposes only.