Free calculator · 2026
UK rental yield calculator
Work out the gross and net yield, the monthly cash flow after the mortgage, and the cash-on-cash return on a buy-to-let. The number that decides it is whether the rent covers the costs. Nothing you type leaves your device.
Track the whole portfolio
The UK Buy-to-Let Portfolio Tracker runs this on every property and the portfolio as a whole: yield, cash flow, ROI, equity and the stamp duty and Section 24 tax view. One offline app, bought once.
How rental yield works
Gross yield is the annual rent as a percentage of the property price, a quick headline. Net yield takes off the running costs (letting fees, maintenance, insurance, voids) but not the mortgage, so it shows what the property earns before financing. Monthly cash flow is what actually lands in your account: rent minus the mortgage and the running costs. A property can show a healthy yield and still be cash-flow negative once a mortgage is on it, which is why this is the figure that really decides a buy-to-let.
Cash-on-cash ROI is the yearly cash flow as a percentage of the cash you put in (deposit plus buying costs), so it tells you how hard your actual money is working. This is an estimate to plan with, not tax or investment advice. It doesn't model the Section 24 mortgage-interest tax change for higher-rate landlords; the full Buy-to-Let Portfolio Tracker does.