How to calculate real rental yield on a flat without fooling yourself

When an estate agent tells you "this flat has an 8% yield", the first thing you should do is take a deep breath and be suspicious. Not because they're lying (well, sometimes they are), but because that figure is usually the gross yield, which is basically useless for making an investment decision.

The one that really matters is the net yield. And getting to it means adding up four or five items that most buyers ignore until it's too late.

The basic calculation everyone gets wrong

The formula for gross yield is simple:

Gross yield = (Annual rent / Purchase price) × 100

A €100,000 flat that you let for €700/month → €8,400/year → 8.4% gross. Sounds good. But wait.

What nobody puts in the spreadsheet

• IBI (the annual local property tax): Between €300 and €800 a year, depending on the municipality. The owner pays it unless you negotiate otherwise.
• Community fees: €50-150 a month in ordinary flats. More if there's a pool, a porter or an old lift.
• Home insurance: Compulsory if you have a mortgage. €200-400/year.
• Void periods and unpaid rent: Statistically, a rental flat is empty for between 1 and 2 months a year, between tenancies or because of non-payment. That's €700-1,400 you don't collect.
• Maintenance and repairs: Allow 1% of the flat's value a year. On a €100,000 flat, set aside €1,000.
• IRPF (the income tax paid by Spanish tax residents) on the income: Rental income is taxed. With the 50% reduction and applying your marginal rate, you could be paying between 15% and 25% of what you collect.
• Purchase costs: Notary, Land Registry, ITP (the property transfer tax, if it's a resale) or IVA (VAT, if it's new), gestoría (the agency that handles the paperwork)... between 8% and 12% of the price. Spread it as a cost to be amortised over 10 years.

The real formula you should use

Net yield = ((Annual rent - Total annual costs) / (Purchase price + Purchase costs)) × 100

Using the same example: €8,400 of income - €3,200 of costs = €5,200 net / €112,000 (price + costs) = 4.6% real. Very different from the 8.4% we started with.

When does it make sense to invest?

In Madrid or Barcelona, a real net yield of 3-4% is already reasonable, because the asset's appreciation makes up for it. In medium-sized cities, it makes no sense below 5% net. With bank-owned or auction properties, where the entry price is 30-40% below the market, achieving 6-8% net is perfectly possible. That's where the money is.

The smart shortcut

Before you get the calculator out, filter down to the properties that, mathematically, already start from a good price. If you buy at market price, the net yield rarely exceeds 4%. If you buy a bank-owned property at a 35% discount, you start the race from kilometre 35. That initial difference is what turns a mediocre investment into an excellent one.

Keep learning: Also read how real property ROI works and why the figure you're given always lies. Or, if you'd rather get straight down to business, see the bank repossession opportunities with verified discounts.