Rental Yield vs ROI: Which Number Should UK Investors Trust?

"Yield" and "ROI" are the two numbers UK property investors argue about most — often because they mean slightly different things to different people. This guide defines each one clearly, shows how they relate, and tells you which to use for which decision.

Gross rental yield

Gross yield = annual rent ÷ property value × 100.

It's the headline rental performance metric — useful for comparing properties at a glance, but it ignores costs and leverage entirely. A property at £150k renting at £950/month has a gross yield of (£950 × 12) ÷ £150,000 = 7.6%.

Net rental yield

Net yield = (annual rent − annual operating costs) ÷ property value × 100.

Operating costs include management, maintenance, insurance, ground rent, service charge, voids, licensing — everything except mortgage interest and tax. Net yield gives you a property-level view of return without distortion from financing decisions or your personal tax position.

Cash-on-cash ROI

ROI = annual net cash flow ÷ total cash invested × 100.

Cash invested includes deposit, stamp duty, legal fees, refurb and any other money you put in to get the property tenanted. Net cash flow is rent minus all costs including mortgage interest. Cash-on-cash ROI is the metric that actually tells you whether your money is working harder in this deal than it would in another investment.

When to use each metric

Use gross yield to

• Compare areas at a glance.
• Filter incoming deals quickly.
• Check that a property is in roughly the right ballpark.

Use net yield to

• Compare properties on a level playing field, regardless of how each is financed.
• Track the underlying performance of a property you already own.
• Discuss deals with other investors on a like-for-like basis.

Use cash-on-cash ROI to

• Decide whether to buy a specific deal with a specific deposit.
• Compare a property purchase against alternative uses of the same cash.
• Track the actual return on each pound of equity you have in a portfolio.

How leverage changes the picture

Leverage amplifies both yield and ROI — but in different directions. Higher leverage usually reduces net cash flow (because more interest), but increases cash-on-cash ROI (because much less of your own money is in the deal). That's the entire reason BRRR and high-LTV property investing exist as strategies.

It's also why ROI alone is a misleading scaling metric: you can engineer a high ROI by minimising cash in the deal, even if the absolute cash flow is too small to be worth managing. Always look at ROI and the absolute monthly cash flow.

Capital growth: the missing variable

None of these metrics include capital growth, which over a 10–20-year hold is often a much larger contributor to total return than rental yield. To compare two areas honestly you need to overlay your assumptions on capital growth on top of cash-on-cash ROI.

Conservative UK assumption: 2–3% annual capital growth over the long run, with significant short-term volatility. Some regional cities have outpaced that materially over the last decade; some southern markets have undershot.

Don't forget tax

Yield and ROI are usually quoted pre-tax. Section 24 means individual landlords can no longer deduct mortgage interest from rental income before tax — they receive only a 20% tax credit on the interest. For a higher-rate taxpayer, that turns a healthy pre-tax cash flow into a much thinner after-tax cash flow, which is why limited company structures have grown so popular for new BTL purchases.

Quick UK benchmarks for 2026

• Gross yield: 4–6% standard for southern single lets, 7–10% for northern and Midlands single lets, 10–15% for HMOs.
• Net yield: knock 1.5–2.5% off gross.
• Cash-on-cash ROI: 5–8% is decent for a single-let purchase today; 12%+ for a successful HMO or BRRR.

For more on how these numbers feed into deal selection, see how to analyse a property deal and BRRR strategy explained.