The commonest mistake in residential investment is taking gross yield for net yield. The gap often reaches a third, and it reorders the neighbourhood ranking entirely.
This guide builds the calculation step by step and works it through with Küçükçekmece data.
1. Gross yield: the easy part
Gross yield = (Monthly rent × 12) ÷ Purchase price
Three neighbourhoods, July 2026 data:
| Neighbourhood | Sale /m² | Rent /m² | Gross yield |
|---|---|---|---|
| Atatürk | ₺38,000 | ₺387 | 12.2% |
| Kartaltepe | ₺68,300 | ₺512 | 9.0% |
| Atakent | ₺93,200 | ₺529 | 6.8% |
An investor reading that table picks Atatürk Mahallesi. Now add the other items.
2. Service charges: the most skipped line
Service charges come straight off the yield and differ between neighbourhoods by multiples.
On an estate like Atakent with security, landscaping, covered parking and leisure facilities, the monthly charge can be several times that of an equivalent Sefaköy flat. In an old building the charge is low — but unexpected lump-sum costs appear: lift renewal, roof, plumbing, façade.
The second is more dangerous because it never makes it into the budget. Any calculation on older stock that does not set aside an annual maintenance allowance is incomplete.
3. Void periods
This line never appears in the calculation and it is what most reduces the yield.
If a flat stands empty two months a year, your realised income falls 16.7%. A 12.2% gross yield becomes 10.2% — and the gap to a 9.0% yield in a low-void neighbourhood is no longer large.
What determines void periods:
- Depth of the tenant pool. Populous neighbourhoods (Atakent 93,229, Halkalı Merkez 78,180, İnönü 73,048) let faster.
- Transport. Metrobüs or metro proximity is on its own a reason for a tenant to decide.
- Unit type. 1+1 and 2+1 let faster; 4+1 slower.
- Season. In student areas — Beşyol, because of the İstanbul Aydın University campus — void risk rises over the summer.
4. Tax
Residential rental income is subject to income tax. For rental income earned in 2026 the residential exemption was announced as ₺58,000; anything above it is declared. The filing window is 1–31 March of the following year, and the tax is paid in two instalments, in March and July.
There are two methods for deducting expenses:
- Flat-rate deduction: a percentage set by law is deducted from the amount remaining after the exemption, without documents. Simple.
- Actual expenses: real costs — interest, insurance, depreciation, maintenance — deducted against documents. Usually better in the early years of a mortgage.
Which suits you depends on your borrowing; decide with your accountant. Once you choose a method you must stay on it for two years.
5. The net yield formula
Net yield = [(Monthly rent × months let) − Service charges − Tax − Maintenance allowance]
÷ (Purchase price + Acquisition costs)
Note the denominator: acquisition costs are part of your capital. The deed fee (4% of the sale price, split by law but in practice usually paid by the buyer), the revolving-fund charge, the agency fee, and appraisal and mortgage costs if you borrow.
Those items pull the first year's return down noticeably and feed directly into the payback calculation.
6. Payback: the real number
Payback (years) = Total investment ÷ Annual net rental income
On paper, a 12.2% gross yield pays back in about 8.2 years. But:
- Deduct service charges and a maintenance allowance → about 10% → ~10 years
- Add two months of vacancy a year → about 8.3% → ~12 years
- Add tax and acquisition costs → longer still
So 8 years on paper becomes 12–13 in reality. That is not bad news; it is simply the correct number. We write this so you do not decide on the wrong one.
7. Two things the calculation leaves out
Capital growth. A yield calculation excludes price appreciation. Sale prices in Küçükçekmece rose an average of 40.6% over the past year — independent of yield, and usually a larger item. But it carries no guarantee and is realised only on sale.
Liquidity. Selling a flat can take months, and longer in thin-market neighbourhoods (Fatih, Kemalpaşa, Yarımburgaz). For an investor who might need cash quickly, that constraint matters more than the yield.
Summary: how to build the right ranking
- Calculate gross yield — use it to screen neighbourhoods.
- Deduct service charges and a maintenance allowance.
- Assume a realistic void period — 0.5 to 2 months depending on the neighbourhood.
- Add tax.
- Add acquisition costs to the capital.
- Compute payback from that net figure.
We work through all six in writing for every investment property in our portfolio. "Yields are good in this neighbourhood" is not an investment case; the number at step six is.