Free rental property calculator
Analyze rental property returns — enter purchase price, rent, vacancy, and expenses to see cap rate, cash flow, and cash-on-cash yield, updated live, as you type.
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Does not include capital expenditures, vacancy surprises, or tax benefits. Consult a real estate professional for investment decisions.
Results are estimates. Consult a professional.
How the rental property calculator works
Analyzing a rental property requires separating what the asset earns from what the financing costs. The calculator first computes net operating income (NOI) — the property's income after expenses but before any mortgage payment. From NOI it derives the cap rate, a financing-neutral yield metric. It then layers in your mortgage to produce actual cash flow and cash-on-cash return, showing you what the property really puts in your pocket.
Operating expenses cover property management fees (typically 8–10% of rent), maintenance and repairs, property taxes, landlord insurance, and capital expenditure reserves. Mortgage principal and interest are excluded from expenses so that NOI and cap rate remain comparable across different financing structures.
National Association of Realtors — Rental Property AnalysisWorked example: $350k rental, $2,500/mo rent
Sam is buying a $350,000 rental property. Market rent is $2,500/month ($30,000/year). Vacancy is estimated at 5%, and operating expenses (taxes, insurance, management, maintenance, reserves) run about 40% of effective gross rent. Sam puts 25% down ($87,500) and finances $262,500 at 7%, 30 years.
NOI and cap rate by rent and property price
The table below shows estimated NOI and cap rate across common rental configurations using a 40% expense ratio and 5% vacancy. These are pre-financing figures — mortgage costs are not included.
| Monthly Rent | $250k Property | $350k Property | $450k Property |
|---|---|---|---|
| $1,500 (NOI / Cap) | $9,234 / 3.69% | $9,234 / 2.64% | $9,234 / 2.05% |
| $2,000 (NOI / Cap) | $12,312 / 4.92% | $12,312 / 3.52% | $12,312 / 2.74% |
| $2,500 (NOI / Cap) | $15,390 / 6.16% | $15,390 / 4.40% | $15,390 / 3.42% |
| $3,000 (NOI / Cap) | $18,468 / 7.39% | $18,468 / 5.28% | $18,468 / 4.10% |
Source: National Association of Realtors, Urban Land Institute. Assumes 40% expense ratio, 5% vacancy. NOI = gross rent × 0.95 × 0.60.
Tips for evaluating rental properties
A rental property is a business. Run it like one from the start by stress-testing your numbers before you close.
- Budget for a full month's vacancy per year minimum — Even in strong rental markets, tenant turnover, cleaning, and re-leasing time realistically cost 1–2 months of rent per year. Underwriting at 5% vacancy (18 days) is optimistic for most landlords.
- Set aside 1% of property value annually for repairs — The 1% maintenance rule is a widely used estimate for older homes. New construction may be lower; homes over 20 years old often run higher. Ignoring this expense makes every deal look better than it is.
- Evaluate property management from day one — Even if you plan to self-manage, budget 8–10% of rent for property management in your model. If you burn out managing or move away, you will need it — and the deal should work with it.
- Look for rent growth potential, not just current rent — A market with 3–5% annual rent growth can turn a marginally cash-flow negative deal cash-flow positive within 3–4 years. Model rent growth to see how quickly the position improves.
- Understand local landlord-tenant law before buying — Eviction timelines vary from 30 days to 12+ months by state. In slow-eviction jurisdictions, one bad tenant can cost $10,000–$20,000. Local laws materially affect your effective expense ratio.
Accuracy and limitations
The calculator uses standard real estate underwriting formulas. All results depend on the accuracy of rent, vacancy, and expense inputs — which vary significantly by property condition, location, and management quality. The model does not account for depreciation tax benefits, principal paydown equity, or future rent increases, all of which can materially improve total returns beyond what cash-on-cash return suggests.
Not financial advice — consult a real estate professional for your specific situation.
Rental property terms defined
About this rental property calculator
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