Belgium net salary calculator

Assumptions

Tax year: 2026

Last updated: 2026-10-19

• Belgium uses a simplified annual employee payroll model in this dataset rather than the full official withholding engine.
• ONSS / RSZ is modeled at 13.07% on gross salary with no ceiling in this MVP.
• Federal income tax is estimated with annual progressive brackets of 25%, 40%, 45%, and 50%, less the bracket tax on the tax-free allowance.
• The configured base tax-free allowance for the 2026 estimate is EUR 11,550.
• For a married household, the model transfers enough professional income to bring the lower-income spouse to 30% of combined professional income, capped at EUR 11,780; it applies the benefit only when this lowers estimated household federal tax.
• Payroll-withholding parameters are versioned separately: the legacy 2026 set applies through October 31 and the September 27 royal-decree set applies to remuneration paid from November 1. These parameters do not replace the annual income-tax calculation.
• Dependent children increase the estimated tax-free allowance by EUR 2,130 for one child, EUR 5,130 for two, EUR 11,440 for three, EUR 18,510 for four, and EUR 7,070 per additional child; special family circumstances are excluded.
• Municipal tax is modeled as a user-selected percentage between 0% and 9% applied on top of the post-reduction federal income tax.
• The special social-security contribution is approximated with a simple monthly bracket scale between EUR 0 and EUR 60.
• The optional expat comparison estimates a separate employer-expense reimbursement up to 35% of gross remuneration when annual remuneration is at least EUR 70,000; it is not an automatic tax-free salary conversion. The income-tax saving compares that reimbursement with the same extra payment treated as taxable; ONSS and special social-security contributions on salary are not reduced.

Official sources and verification

Published model: tax estimate; see the limitations listed above.

Tax assumptions reviewed: 2026-10-19

• FPS Finance — tax rates
• Belgian Official Gazette — 2026 payroll withholding amendment
• FPS Finance — inbound taxpayer regime