Rental Property Cashflow Calculator
Monthly money in, money out, and what is left in the bank.
Monthly income
£1,100
Monthly outgoings
£903
Monthly cashflow
£197
Annual cashflow
£2,364
Outgoings as % of rent
82.09%
What this calculator tells you
Cashflow is the number that decides whether a property is comfortable or stressful to own. Yield and ROI are annual abstractions; cashflow is what actually lands in the account each month after the mortgage and everything else has gone out. A property can be a fine long-term investment and still be a monthly drain — you need to know which one you are buying.
How it works
- 1Start with the monthly rent.
- 2Subtract the mortgage payment, management fee, insurance, a maintenance sinking fund and any bills or charges you cover.
- 3Subtract a void allowance so an empty month does not come as a shock.
- 4What remains is your monthly surplus — or the shortfall you need to fund from elsewhere.
Worked example
£1,100 rent with a £650 mortgage payment
- Management at 10% = £110. Void allowance at 5% = £55.
- Insurance £21, maintenance £67.
- Total outgoings: £903.
- £1,100 − £903 = £197 monthly cashflow.
Just under £200 a month, or roughly £2,360 a year — enough to absorb a boiler replacement most years, but not much more.
Frequently asked questions
How much monthly cashflow should a rental produce?
Many landlords use £150–£250 per property per month as a minimum for a single let, on the basis that a single significant repair can easily consume a year of anything less.
Should I include a maintenance sinking fund?
Yes. Setting aside roughly 1% of the property value each year, or about 6% of rent, means boilers, roofs and white goods come out of a fund rather than out of your own pocket at the worst moment.
Related content
These calculators give general estimates for UK private landlords and letting agents, not legal, tax or financial advice. Figures depend on your circumstances and on the rules in your part of the UK — check the detail or take advice before acting.