Rental Income Calculator
Project net rental income after every operating cost and mortgage.
Please note: Estimates only, not investment or legal advice. Property markets, taxes, fees and lending rules vary by location and change over time. Verify figures with a qualified professional before committing.
What the Rental Income Calculator does
Net rental income is what actually reaches your bank account after vacancy, management, maintenance, insurance, tax and mortgage. Gross rent overstates the return dramatically — operating costs alone typically consume 30–50% of it.
Formula
Effective rent = Gross rent × (1 − Vacancy rate)Operating costs = Management + Maintenance + Insurance + Property tax + OtherNOI = Effective rent − Operating costsNet cash flow = NOI − Mortgage − Tax
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Monthly rent | selected currency | Yes | Accepts more than 0. |
| Vacancy allowance | % | Yes | — |
| Monthly mortgage payment | selected currency | Optional | Accepts 0 or more. |
| Management fee | % | Optional | Percent of collected rent. |
| Monthly maintenance | selected currency | Optional | Accepts 0 or more. |
| Monthly insurance | selected currency | Optional | Accepts 0 or more. |
| Monthly property tax | selected currency | Optional | Accepts 0 or more. |
| Other monthly costs | selected currency | Optional | Accepts 0 or more. |
| Tax on rental profit | % | Optional | — |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Currency.
- Enter Monthly rent and Vacancy allowance.
- Optionally add Monthly mortgage payment, Management fee and Monthly maintenance.
- Select Calculate.
Worked example
$2,200 rent, 5% vacancy, $1,350 mortgage, 10% management, $180 maintenance, $95 insurance, $290 property tax.
- Rent
- 2200
- Vacancy
- 5
- Mortgage
- 1350
- Management
- 10
- Maintenance
- 180
Effective rent $2,090, operating costs $774, NOI $1,316 — net cash flow of −$34 a month before tax.
Reading the result
- Check "operating expense ratio" against the 50% rule before reacting to the bottom-line cash flow figure — a ratio well under 50% alongside a weak cash flow number often means the mortgage, not operating costs, is the constraint.
- "Cash flow margin" (against gross rent) is a stricter view than the operating expense ratio (against effective rent), since it nets out the mortgage too — a healthy expense ratio can still pair with a negative cash flow margin once debt service is included.
Assumptions and limitations
- Management fee is charged on effective, post-vacancy rent — a management contract that bills on gross rent before any vacancy credit would cost slightly more than this model shows.
- Maintenance, insurance and property tax are entered as flat monthly figures rather than derived from the property's value, so they need to be kept current manually rather than assumed to scale automatically with rent.
Common mistakes
- Reading a small negative monthly cash flow as an isolated one-off rather than checking whether it is structural via the operating expense ratio — a near-zero cash flow with costs well under 50% of rent is a very different situation from one already above 50%.
- Assuming rental losses automatically offset other income for tax purposes — the "tax on rental profit" line only applies to positive pre-tax cash flow, and this calculator does not model loss offset, which varies by jurisdiction.
Frequently asked questions
What is the 50% rule?
A screening heuristic that operating costs, excluding mortgage, average around 50% of gross rent. If your estimate is far below that, you have probably forgotten something.
Should I self-manage to save the fee?
It saves 8–12% of rent but costs real time and exposes you to tenant issues directly. Model both, and be honest about whether you will actually do the work.