Rental property cash flow calculator
Most cash-flow arithmetic is optimistic because it leaves out the money that has not been spent yet. This one funds vacancy, maintenance and capex first, then tells you what is left.
Pre-filled with the site's example unit, reserves funded. Set management to a market rate even if you self-manage.
Monthly cash flow after reserves and debt service
$158.50
- Gross rent
- $1,850.00
- Effective rent after vacancy
- $1,757.50
- Reserves (maintenance, capex, management)
- $259.00
- Debt service
- $980.00
- Taxes and insurance
- $360.00
- Monthly cash flow
- $158.50
- Annual cash flow
- $1,902.00
- Monthly NOI (before debt)
- $1,138.50
- Expense ratio
- 33.46%
Why the reserves come out first
A roof does not cost nothing for eighteen years and then $14,000. It costs about $65 a month for eighteen years, and you find out in month 216. A unit that is only positive when the reserve lines are blank is a unit that will hand you a bill you have not funded.
| Line | Typical band | What sets it |
|---|---|---|
| Vacancy | 4–8% | Your turnover rate and days to re-let |
| Maintenance | 5–10% | Age of the building and quality of the last rehab |
| Capex | 5–10% | Remaining life of roof, HVAC, water heater |
| Management | 0–10% | Zero only while you genuinely do the work |
Management at zero is a wage you are not paying yourself
If the unit only clears with your own labour uncounted, put a real number in the management field and see whether it still clears. That is the number that matters when you buy the second one.
Cash flow, NOI and cap rate are three different questions
- Cash flow is what lands in your account this month, after the mortgage.
- NOI is what the building earns before financing — the number a buyer compares.
- Cap rate is NOI over price; it prices the building, not your loan.
Take the same inputs into the cap rate calculator and the cash-on-cash return calculator and you get the three answers a buyer, a lender and you each care about.
Feeding the vacancy number honestly
Vacancy is not a percentage you pick; it is your own turnover rate times your own days-to-let. If you turn one unit every two years and re-let in 24 days, that is roughly 3.3% — but the turnover cost calculator will show you the make-ready sitting behind it, which is the larger number and belongs in capex, not vacancy.
Related in the binder
