The calculator

Fill in your assumptions in the black block. Results update live in the light block just below. All calculations run in your browser — nothing is sent to a server.

🏠 The property

Determines the registration duty rate.
Renovation, EPC compliance, furniture, etc.

💳 Financing

Cash put down at purchase (excl. fees).

💶 Rental income

Excluding recoverable charges.
5% ≈ ~2 empty weeks / year + small unpaid rent.
0 if you manage it yourself, 7-8 if via agency.

📉 Recurring charges

For an apartment. Set to 0 for a house.
Estimate: cadastral income × regional rate × surcharges.
Usually 0.5 to 1% of the purchase price.

📋 Taxation

The tax regime drastically changes the net yield.
25, 40, 45 or 50% in Belgian personal income tax.

📈 Exit & projection

Belgian historical ≈ 2 to 3% / year.

📊 Your results

Gross yield
Annual rent / total cost
Net yield before tax
Excluding taxes and mortgage
Net yield after tax
Net of income tax
Monthly cash flow
After mortgage and charges

🧱 Acquisition costs

Total acquisition cost
Invested capital (cash out)
Registration duties
Notary fees
Mortgage fees
Monthly mortgage payment

📈 Projection at exit

Estimated resale value
Cumulative cash flow over the period
Net proceeds from sale
Total gain
Total ROI over the period
Annualised IRR

📊 Year-by-year evolution

How your investment behaves each year, and where you'll stand at exit.

💸 Annual cash flow

Net rental income − mortgage payments. Negative = monthly savings effort.

🏦 Outstanding loan balance

What you still owe the bank, which melts away over the years.

📈 Property value & equity

The gap between property value and outstanding loan = your equity.
Property value Equity (value − debt) Outstanding loan

🥧 Acquisition cost breakdown

What you actually pay on top of the purchase price.

🗓️ Detailed timeline — year by year

Year Cash flow Capital repaid Outstanding loan Property value Equity

What do the indicators mean?

1
Gross yield Annual rent divided by the total acquisition cost (price + duties + notary + mortgage + works). This is the marketing figure — the one agencies put forward. It ignores all charges. Above 6% gross in Belgium is already very good.
2
Net yield before tax Net rent (after vacancy) − charges (co-ownership, property tax, insurance, maintenance, management), divided by total cost. This is the real yield of the operation, before personal taxation. This is what you should compare across projects.
3
Net yield after tax We deduct the tax on rental income. In Belgium, unfurnished rental to a private tenant remains very advantageous: you are taxed on the indexed cadastral income × 1.40, not on actual rent. Furnished rentals and renting to a professional change the picture.
4
Monthly cash flow The most concrete metric: how much you put in from your pocket each month (or pocket as extra income). Negative = monthly savings effort. Positive = self-sustaining operation. This is the indicator that tells you whether you can hold the property.
5
Total ROI & IRR Total gain (cumulative cash flow + net capital gain − invested capital) measured against your invested capital. The IRR annualises this return, allowing you to compare with other investments (ETFs, savings account, etc.).

Calculation assumptions

To stay transparent, here is exactly what the calculator does behind the scenes:

ItemAssumption used
Registration duties 2% Flanders / 3% Wallonia / 12.5% Brussels with €200,000 abatement (if price ≤ €600k) for sole primary residence. 12 / 12.5% otherwise.
Notary fees Approximation: 1.2% of the price + €1,500 of administrative fees.
Mortgage fees 2% of the borrowed amount (mortgage right 1% + notary/registration fees ~1%).
Monthly mortgage payment Constant annuities — classic formula with the fixed rate and term entered.
Property tax You enter it. Quick estimate: 0.3 to 0.5% of the purchase price per year (very variable depending on the municipality).
Tax — unfurnished to private tenant Cadastral income ≈ 0.5% of price × index 2.1761 × 1.40, taxed at marginal rate. Approximation: the real cadastral income is officially registered.
Tax — furnished 60% of rent = movable income (30% tax after 50% lump-sum allowance) + 40% treated as unfurnished property.
Tax — to a professional Actual rent − 40% lump-sum costs, taxed at marginal rate.
Indexation Rent is indexed every year. Charges follow a similar path.
Capital gain at resale Value = price × (1 + appreciation)^period. Lump-sum resale fees: 3% (agency + seller's notary). No capital gains tax integrated (except exceptional cases not covered here).
Total ROI (Net sale proceeds + cumulative cash flow − invested capital) / invested capital. IRR annualised over the holding period.
⚠️ What this calculation does not do

This tool gives a preview of profitability, not a financial plan. It does not cover: purchase via a company (BV/SRL), VAT if the property is new, deduction of loan interest on professional income, capital gains tax in case of quick resale outside primary residence, nor ongoing legislative changes. For a real decision, get your numbers validated by an accountant, a notary or an investment advisor.

How to read a result

Three patterns recur in Belgium:

🟢 Positive cash flow + net yield > 4%

Solid operation. Often a yield property in the provinces, purchase without agency, little co-ownership, financing with reasonable down payment. The property funds itself.

🟡 Cash flow ≈ 0, yield 2-3%, expected capital gain

Typical case of an apartment in Brussels or first ring. You're betting mainly on long-term appreciation. Doable if you have the shoulders for it.

🔴 Cash flow clearly negative, yield < 2%

Significant monthly savings effort. Justifiable only if you have a real capital gain thesis or a specific wealth objective. Renegotiate, otherwise pass.

And above all — compare to the alternative

A property investment only makes sense compared to what you can do otherwise with the same capital. An IRR of 4% over 20 years is broadly what you'd expect from a diversified global ETF — without any of the rental hassle. The question isn't "is it profitable?", but "is it more profitable and acceptable than my other options?"

🎯 Not sure you're ready to buy?

The Decisio quiz analyses your situation and tells you if buying makes sense — or whether renting remains the right option for now.

Take the quiz →