Rental yield and cash flow calculator
Check whether a buy-to-let pays its way: yields, monthly cash flow after interest, and the return on the cash you put in.
Key facts
- Gross yield = annual rent ÷ price.
- Net yield takes off running costs first.
- Cash-on-cash return = yearly cash flow ÷ your deposit and buying costs.
- Results are before tax. Section 24 means you can owe tax even with thin cash flow.
Reading the results
Gross yield is the quick figure agents quote. Net yield is more honest. A common allowance for agent fees, insurance, maintenance and empty periods is 15–25% of rent. Cash flow is what's left after costs and interest, before tax.
Stress-test the deal
Try a mortgage rate two points higher, one empty month a year, and costs 20% higher. If cash flow stays positive, the deal has a margin of safety. Then run the profit through the landlord tax calculator. From April 2027 rental profit is taxed at 24% to 49%.
Frequently asked questions
What is a good rental yield in the UK?
It depends on the area and property type. Gross yields of 5–7% are common outside London. Central London is often lower. Net yield and cash flow matter more than gross yield.
Does this include Stamp Duty?
Include it in buying costs. Use our buy-to-let Stamp Duty calculator to get the figure.
Sources
- GOV.UK: Work out your rental income when you let property
- GOV.UK: Stamp Duty Land Tax residential property rates
Sources last checked 9 November 2026. See all our sources and how we keep pages up to date.