🇧🇪 Belgium net salary calculator (bruto-netto)
Your Belgian net salary is gross minus RSZ social security and progressive income tax, after professional costs, the tax-free sum and the municipal surcharge.
✓ Verified against 2 self-test cases Updated for 2025 · sources checked 2026-08-02
How netto loon in Belgium is calculated
Belgian payroll deducts RSZ/ONSS social security of 13.07% from gross, then allows a professional-costs deduction (a 30% forfait, capped) before tax.
Withholding tax is steeply progressive (25% to 50%), reduced by the tax-free sum, with a municipal surcharge of around 7% added on top. The calculator shows the contributions and taxable base. Estimate, not tax advice.
Worked example
| grossAnnual | 45000 |
|---|---|
| rsz | 5881.5 |
| profCosts | 5930 |
| taxable | 33188.5 |
Frequently asked questions
What is the taxable base for 45,000 EUR in Belgium?
RSZ takes 5,881.50, the professional-costs forfait is capped at 5,930, leaving a taxable base of 33,188.50 EUR before the progressive scale.
What is the municipal surcharge?
Communes add a surcharge (opcentiemen) of typically 6-9% on the income tax, so the same salary nets slightly differently by town.
Why are Belgian taxes so high?
The withholding scale reaches 50% quickly, which is why the tax-free sum and professional-costs deduction matter so much.
Sources
- FOD Financiën Tax-Calc · checked 2026-08-02
- RSZ · checked 2026-08-02
Estimate. Not tax advice. The verification badge means the model reproduces the stated formula through 2 self-test cases; the sources support that the formula matches the rules.
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