⚠️ An estimate, not a payslip
The calculator applies the official 2026 rates to an ordinary, full-time monthly salary. It does not include bonuses, overtime, benefits in kind, meal vouchers, company health insurance or provident schemes (except what you enter), collective agreements, special schemes (apprentices, students, flexi-jobs, cross-border workers…) or the Belgian municipal tax. Your payslip is what counts: if in doubt, ask your employer or payroll office.
How is net pay calculated in Belgium?
First, the personal social security (ONSS/RSZ) contribution is deducted: 13.07% of gross pay (on 108% of gross for blue-collar workers). For low wages, the work bonus reduces this contribution (up to €299.53 a month for a white-collar employee in 2026).
The employer then withholds professional withholding tax, computed with the official key formula of the FPS Finance: flat-rate professional expenses (30%, up to €6,070 a year), tax brackets from 26.75% to 53.50%, tax-free allowance, reductions for dependent children, marital quotient if your spouse has no income, and the tax reduction linked to the work bonus.
Finally, the special social security contribution is withheld every month (between €0 and €60.94). Withholding tax is an advance: your final tax, including the municipal tax, is calculated the following year.
Official sources used (2026)
- France: order of 22 December 2025 (2026 Social Security ceiling), URSSAF private-sector rates, 2026 Agirc-Arrco rates, neutral withholding tax scale (article 204 H of the General Tax Code, 2026 Finance Act). Results checked against URSSAF’s official calculation model (mon-entreprise.urssaf.fr).
- Belgium: annex III to the Royal Decree implementing the Income Tax Code (2026 withholding tax, Royal Decree of 11 December 2025), ONSS administrative instructions (contributions, work bonus from 1 September 2026, special social security contribution).
Frequently asked questions
How much is €3,000 gross in net pay in Belgium?
For a single white-collar employee without children, about €2,253 net a month in 2026 (ONSS after work bonus: €281.56; withholding tax: €437.87; special contribution: €27.51).
What is the work bonus?
A reduction of the ONSS contribution for gross salaries up to €3,403.62 a month (full-time white-collar employee, since September 2026), plus a reduction of withholding tax.
Is withholding tax my final tax?
No, it is an advance. Your final tax, including the municipal tax, is calculated in the tax assessment the following year.
See also : Gross to net · France
💡 Got an idea for a small tool? Tell us what you’re missing: every month we build the most requested idea, for free.
Suggest an idea