Tax-Calc: estimate your Belgian personal income tax anonymously (FPS Finance).

Details

• Source: https://financien.belgium.be/nl/E-services/Tax-calc
• Direct link to the simulation (tax year 2026): https://ccff02.minfin.fgov.be/taxcalc2026/app/anonymous/public/calcbox/home.do
• Organisation: FPS Finance (FOD Financiën)
• Type: calculator/simulation (anonymous, no login with eID or itsme® required)
• Topic: personal income tax — estimate of what you may have to pay or get back
• Cost: free

What is Tax-Calc?

Tax-Calc is the official FPS Finance simulator that lets you anonymously estimate your tax amount. You enter your situation (income, household situation, deductions, …) and the tool calculates how much personal income tax you will likely have to pay extra or get back.

Important:

• It’s an estimate, not a tax assessment notice. The final calculation is done via your tax return and processing by the tax authorities.
• It doesn’t change anything in your file: a simulation is not a tax return.

What do you use it for (and what not for)?

Yes:

• Estimating what to expect in personal income tax on your self-employed profit.
• Comparing scenarios: low / medium / high income, or with and without certain professional expenses.
• Estimating your advance payments per quarter so you don’t get surprised.
• Preparing for a conversation with your accountant.

No:

• Calculating your social security contributions — that’s a separate calculation via your social insurance fund (see the article about social-contribution simulators).
• Submitting your tax return — that’s done via MyMinfin (Tax-on-web).

How to use the tool (practical)

1. Go to the FPS Finance landing page and start the anonymous calculation for the correct tax year.
2. Choose your language (the tool starts with a language selection).
3. Enter your household situation (marital status, dependants, …).
4. Enter your income. If you’re self-employed: your expected net taxable professional income (profit after professional expenses), plus any other income (salary, student job income, …).
5. Enter your deductions where applicable (e.g. mortgage, childcare, pension savings).
6. Review the estimate and repeat with 2–3 scenarios. Write down your assumptions each time.

What should you pay attention to?

• Enter your total income, not only your self-employed profit. If you combine a student job or salary with your business, they are taxed together — which can push you into a higher bracket.
• Net taxable ≠ revenue. First subtract your professional expenses (actual costs or the flat-rate deduction) before you enter an amount.
• The direct link contains the year (taxcalc2026). Each tax year gets a new URL — when in doubt, always start from the FPS Finance landing page. Previous tax years are listed there under a separate link.
• Social contributions are deductible as a professional expense, but they are not taxes. If you want to know what you really keep net, combine both calculations.

Tips for (student) self-employed people

• If your income fluctuates, simulate multiple scenarios and repeat this every six months.
• If you’re close to a threshold amount (staying fiscally dependent, thresholds for social contributions), discuss it in time with your accountant and your social insurance fund.
• Think broader than taxes: your income can also affect your Groeipakket, study grant, or other rights.

Related articles

• Simulating social contributions: calculators from the social insurance funds
• FPS Finance calculator – dependants
• Submitting your tax return (MyMinfin / Tax-on-web)
• Flat-rate professional expenses as a self-employed person: pros and cons
• Threshold amounts 2026 (social contributions & personal income tax)

Link

• https://financien.belgium.be/nl/E-services/Tax-calc