Rental property investment calculator guide
This calculator estimates a long-term residential rental’s pre-tax cash flow, operating return, mortgage paydown, equity, and possible proceeds from a future sale. Use scenarios to compare properties, financing choices, or different assumptions side by side.
What it calculates
The calculator models one aggregate property month by month. It applies vacancy to scheduled rent and other income, subtracts management and maintenance from collected income, subtracts fixed operating expenses, and keeps a capital expenditure reserve separate from net operating income. If the purchase is financed, the same monthly projection splits each fixed-rate mortgage payment between interest and principal.
Rent and other income grow at the start of each property year. Fixed-dollar expenses follow the expense-inflation assumption. Property value follows the appreciation assumption, while mortgage interest, principal, and balance come from the amortization schedule rather than from an annual approximation.
When Model sale at end is on, the property is sold after the final mortgage payment in the selected holding year. Selling costs and the remaining loan balance are subtracted from the projected value. The calculator also evaluates a hypothetical sale after each year from 1 through 30. Turning the sale off preserves the selling-cost assumption but removes sale proceeds, profit, total return, IRR, and sale-year comparisons from that scenario.
Questions it answers
How much cash is needed?
Initial cash required combines the down payment, purchase closing costs, and initial renovations. The cash-position chart adds later negative operating months to the owner’s cumulative contributions.
Does the first year cover itself?
Monthly cash flow, annual cash flow, NOI, cap rate, cash-on-cash return, DSCR, and break-even occupancy show the first year from operating and financing perspectives.
What might a later exit look like?
Property value, mortgage balance, equity, sale proceeds, nominal profit, total return, and levered IRR describe the selected holding period when a sale is modeled.
Which assumption changes matter?
Up to five scenarios can compare properties or stress one property with a different down payment, vacancy rate, rent growth, expense inflation, appreciation rate, or holding period.
Major inputs
- Purchase price and down payment
- The property price and the amount paid toward it at purchase. Down payment may be entered as dollars or as a percentage; the remainder is the original mortgage balance.
- Mortgage rate and term
- The annual rate and repayment period for one fixed-rate amortizing mortgage. A 100% down payment models an all-cash purchase.
- Closing costs and renovations
- Upfront transaction costs and initial make-ready work. Both increase cash invested; renovations do not automatically increase the modeled property value.
- Rent, other income, and vacancy
- Aggregate scheduled monthly income for the whole property. Vacancy reduces both rent and other income before percentage-based costs are calculated.
- Property tax, insurance, and HOA
- Tax and insurance are annual dollar amounts. HOA is monthly. These are operating expenses even when a lender collects some of them through escrow.
- Management and maintenance
- Percentages of income after vacancy. They scale with collected income rather than with the purchase price.
- Capital expenditure reserve
- A percentage of collected income set aside for irregular replacement costs. The reserve reduces cash flow but is excluded from NOI and is not treated as a separate investment account.
- Additional owner-paid costs
- Monthly utilities and other operating expenses such as lawn care, pest control, or licensing. These fields are grouped in the collapsed Additional costs section.
- Growth and inflation
- Rent growth also applies to other income. Expense inflation applies to fixed-dollar expenses. Both step annually rather than changing every month.
- Appreciation and holding period
- The assumed annual change in property value and the whole-number year used for the selected projection and sale.
- Model sale and selling costs
- The sale toggle decides whether exit results are included. Selling costs are a percentage of the projected sale price and remain saved while the sale is off.
What the results mean
- Monthly and annual cash flow
- Year-one NOI minus the capital reserve, mortgage interest, and mortgage principal. Monthly cash flow is the annual amount divided by 12.
- Year-one NOI and cap rate
- Effective income minus operating expenses, excluding reserve and financing. Going-in cap rate divides that NOI by purchase price.
- Cash-on-cash return
- Year-one pre-tax cash flow divided by initial cash required. It is shown as N/A when the initial cash denominator is zero.
- DSCR
- Year-one NOI divided by annual mortgage debt service. An all-cash purchase has no debt service, so DSCR is N/A rather than infinite.
- Break-even occupancy
- The occupancy that makes year-one cash flow zero after re-running percentage expenses at each occupancy level. >100% means full occupancy still would not cover the modeled costs.
- Equity
- Projected property value minus the remaining mortgage balance. The equity chart separates the value and loan lines and shades the gap between them.
- Net sale proceeds
- Projected sale price minus selling costs and mortgage payoff. A negative figure is labeled cash required to sell.
- Total owner contributions
- Initial cash required plus every later negative monthly operating cash flow. Those later deficits are counted once as contributions and are not subtracted from profit a second time.
- Total nominal profit and return
- Signed cumulative operating cash flow plus net sale proceeds minus initial cash required. Total return divides that profit by total owner contributions.
- Levered IRR
- An annualized time-weighted result from the initial investment, monthly operating cash flows, and final sale proceeds. The calculator reports N/A when the cash-flow sequence does not have one unambiguous sign change.
The six chart sections show first-year rent, annual cash flow, property value and equity, cumulative cash invested and returned, profit sources, and alternative sale years. Waterfalls and annual breakdowns keep one aligned lane per scenario. The cash-position chart always draws invested and returned lines for every enabled scenario. Sale proceeds stay out of the ordinary annual operating column so they do not flatten the rest of the chart.
Worked example
Hypothetical: a $350,000 long-term rental
Use a $350,000 purchase price, 25% down, a 6.5% 30-year mortgage, 3% purchase closing costs, and $10,000 of initial renovations. Assume $3,000 monthly rent, 5% vacancy, 8% management, 5% maintenance, a 5% capital reserve, $4,200 yearly property tax, and $1,600 yearly insurance. Leave other income, HOA, utilities, and other owner-paid costs at zero.
For the projection, use 3% yearly rent growth, expense inflation, and property appreciation, a ten-year holding period, 6% selling costs, and keep the sale toggle on.
Under smooth assumptions, the property value is about $470,371 after ten years, the mortgage balance is about $222,537, and modeled net sale proceeds are about $219,611 after selling costs and loan payoff. These are nominal pre-tax estimates, not a prediction. Duplicate the scenario and vary vacancy, repairs, rent growth, appreciation, and the exit year before relying on the shape of the result.
Assumptions and limitations
- The model supports one long-term residential property entered in aggregate, one fixed-rate mortgage or an all-cash purchase, and one optional sale. It does not model leases, tenants, units, short-term-rental seasonality, refinancing, adjustable rates, balloon payments, partnerships, or commercial underwriting.
- Values are nominal and pre-tax. The calculator does not estimate income tax, depreciation, passive-loss limits, capital gains, depreciation recapture, basis adjustments, or a 1031 exchange. IRS Publication 527 shows why an actual rental tax result requires facts and rules outside this model.
- Rent, expenses, and property value follow smooth annual rates. Actual vacancy, repairs, assessments, financing terms, and sale prices are uneven and uncertain.
- The capital reserve is a planning expense, not a prediction of when major work occurs and not a balance that earns a return. Initial renovations add to cash invested without automatically adding to value.
- Total return is a nominal holding-period ratio, not an annual rate. Levered IRR can be unavailable or misleading when cash flows change direction more than once, and it should be read with the dollar profit and cash-position chart.
- Closing-cost and mortgage fields are planning inputs. Compare them with the lender’s Loan Estimate and include any material costs that the calculator does not name explicitly.
Calculations are estimates for planning and education, not personalized financial, tax, accounting, legal, real-estate, or investment advice. Actual results may differ. Read the Financial Disclaimer.
Sources and further reading
Sources reviewed August 2026. These sources explain U.S. mortgage and rental-property concepts; they do not endorse this calculator or its assumptions.
- Consumer Financial Protection Bureau: How paying down a mortgage works — principal, interest, balance, equity, and fixed-rate amortization.
- Consumer Financial Protection Bureau: Loan Estimate explainer — loan terms, principal and interest, closing costs, taxes, insurance, and cash to close.
- IRS Publication 527, Residential Rental Property — rental income, expenses, depreciation, reporting, and tax topics deliberately outside this pre-tax calculator.