Rental Property Cash Flow Calculator
Model monthly rental cash flow after mortgage, tax, insurance and reserves, with cash-on-cash return, DSCR, cap rate and the break-even rent.
Monthly income
Monthly fixed costs
Reserves, as a percentage of rent
Where the rent goes each month
| Rent and other income | $2,200.00 |
| Mortgage principal and interest | −$1,199.10 |
| Property tax | −$250.00 |
| Insurance | −$100.00 |
| HOA / strata | −$0.00 |
| Owner-paid utilities | −$0.00 |
| Vacancy allowance (5.0%) | −$110.00 |
| Maintenance reserve (5.0%) | −$110.00 |
| Capital expenditure reserve (5.0%) | −$110.00 |
| Property management (8.0%) | −$176.00 |
| Total going out | $2,055.10 |
| Monthly cash flow | $144.90 |
Deal metrics
| Loan amount | $200,000 |
| Total cash invested | $56,000 |
| Net operating income (a year) | $16,128 |
| Cap rate on purchase price | 6.45% |
| Annual debt service | $14,389 |
| Break-even monthly rent | $2,011.82 |
| Debt service coverage | Covers the debt, but thinner than most lenders want |
The mortgage payment uses the standard annuity formula P·r(1+r)n / ((1+r)n − 1) — a $200,000 loan at 6% over 30 years gives $1,199.10 a month, which matches any published amortisation table. Cash-on-cash return is annual cash flow ÷ cash invested, and DSCR is net operating income ÷ annual debt service, with NOI excluding the mortgage by definition. Income tax, depreciation and appreciation are not modelled. Arithmetic only, not investment advice.
What is the Rental Property Cash Flow Calculator?
The ByteTools Rental Property Cash Flow Calculator works out what a rental actually puts in your pocket each month.
- Mortgage payment from the standard annuity formula, not an estimate
- Vacancy, maintenance, capex and management reserves as a share of rent
- Cash-on-cash return based on down payment, closing costs and rehab
- DSCR with the usual 1.25 lender benchmark called out
- Break-even monthly rent solved allowing for the rent-linked reserves
- Private, offline arithmetic — no property data is fetched or stored
How to use the Rental Property Cash Flow Calculator
- 1
Enter the purchase price, down payment, mortgage rate and term, plus closing costs and any upfront repairs.
- 2
Add the monthly rent and any other income such as parking or pet rent.
- 3
Fill in the fixed monthly costs: property tax, insurance, HOA and any owner-paid utilities.
- 4
Set the reserve percentages for vacancy, maintenance, capital expenditure and property management.
- 5
Read the cash flow, cash-on-cash return and DSCR in the tiles, then check the two breakdown tables.
About the Rental Property Cash Flow Calculator
The ByteTools Rental Property Cash Flow Calculator works out what a rental actually puts in your pocket each month. It calculates the mortgage principal and interest from the standard annuity formula, subtracts tax, insurance, HOA and utilities, then applies vacancy, maintenance, capital expenditure and management reserves as a percentage of rent — the four costs most beginner spreadsheets forget.
From there it rolls up to annual cash flow, cash-on-cash return on the money you actually put in, net operating income, the cap rate on your purchase price, the debt service coverage ratio your lender will look at, and the rent at which the deal breaks even.
It is built for landlords underwriting a purchase and for owners checking whether an existing property still works. Everything is computed in your browser with nothing uploaded. Income tax, depreciation and appreciation are not modelled, so treat the output as a screening estimate, not investment advice.
Frequently asked questions
How do you calculate rental property cash flow?
Take the monthly rent and other income, then subtract the mortgage payment, property tax, insurance, HOA, utilities and your reserves for vacancy, maintenance, capital expenditure and management. What is left is monthly cash flow; multiply by twelve for the annual figure.
What is a good cash-on-cash return?
Many buy-and-hold investors look for 8% or better, though what counts as good depends on the market, the leverage used and how much appreciation you expect. The figure is annual cash flow divided by the cash you actually invested, so it moves sharply with the size of your down payment.
What is DSCR and why does it matter?
Debt service coverage ratio is net operating income divided by annual mortgage payments. Lenders on investment property usually want 1.25 or better, meaning the property earns 25% more than it needs to service the debt. Below 1.0 the rent does not cover the loan.
How much should I budget for maintenance and capex?
A common starting point is 5% of rent for routine maintenance and another 5% for capital expenditure like roofs and HVAC, but older properties need more. Both percentages are editable here so you can match your own experience with the building.
Why is the mortgage excluded from net operating income?
NOI is a property measure, not a financing measure, so it deliberately leaves out loan payments. That is what lets you compare two buildings independently of how each buyer paid for them, and it is why the cap rate uses NOI rather than cash flow.
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