The calculator

Enter your monthly gross and your family situation. The calculation updates live and shows the breakdown of each item (ONSS, personal income tax, employment bonus, special contribution). For the line-by-line reading of those items, see understanding your Belgian payslip.

💼 Your salary

The gross amount shown on your payslip or contract.
≈ 92% of gross, paid in June/July.

👨‍👩‍👧 Family situation

Activates the marital quotient — additional tax-exempt allowance.
Increases the tax-exempt allowance (1 child = +€1,850 · 2 = +€4,760 · 3 = +€10,660).

🍕 Fringe benefits

Employer share exempt up to €6.91/day.
Exempt up to €250/year.

ℹ️ Good to know

The calculation uses simplified 2026 personal income tax brackets. Accuracy is ±2-3% vs your actual payslip (which depends on your employer's payroll software and precise parameters such as your municipality, seniority, etc.).

💰 Your results

Monthly net
—
Smoothed over 12 months
Annual net
—
With 13th + holiday pay
Total net (+ fringe benefits)
—
Incl. meal + eco-vouchers
Net / gross ratio
—
Monthly

📊 From gross to net — monthly breakdown

🔍 Calculation details

Total annual gross—
Monthly ONSS (13.07%)—
Annual ONSS—
Flat-rate professional expenses—
Net taxable income—
Tax-exempt allowance—
Annual personal income tax—
Monthly personal income tax (approx.)—
Special social security contribution—
Employment bonus (annual)—
Effective tax rate—

🍱 Fringe benefits

Meal vouchers (annual net value)—
Annual eco-vouchers—
—

How it works, from gross to net

1
ONSS — Social security contributions 13.07% of gross is withheld first. These contributions fund your social security (unemployment, pension, sickness, disability).
2
Flat-rate professional expenses The State automatically deducts 30% of your taxable income (capped at 5 930 €/year) before calculating the tax — no receipts required.
3
Professional withholding tax — Personal income tax Calculated by brackets: 25 % (0–16 320 €) · 40 % (16 320–28 800 €) · 45 % (28 800–49 840 €) · 50 % (above). The tax-exempt allowance (10 910 € base) is not taxed: it is imputed on the lowest brackets. Children increase it.
4
Special social security contribution Small annual contribution (€0 to €430) depending on your taxable income. Often forgotten in DIY calculations.
5
Employment bonus For low salaries (≤ €3,320 gross/month), a reduction of the withholding tax can reach €272/month. That's what makes the net/gross ratio very favourable for modest incomes.
💡 The marginal rate catches everyone out

On your last gross euro, you pay 50% tax + 13.07% ONSS = more than 60% in direct deductions as soon as you exceed 49,840 € of annual taxable income (~€5,300 gross/month). That's why a €300 gross raise turns into only ~€120 net — a key point to keep in mind when you negotiate a raise.

How to optimise legally?

1
Maximise fringe benefits Meal vouchers (~€70/month net), eco-vouchers (€250/year), hospitalisation insurance, business phone/laptop. These benefits are exempt or lightly taxed — that's pure net.
2
Pension savings Up to 30% tax reduction on €1,050/year (or 25% on €1,350). Direct tax saving. See our guide on the 2026 pension savings cap choice.
3
Cafeteria plan Convert part of the gross into benefits (car, insurance, IT) instead of salary taxed at 50%.
4
Actual professional expenses If you declare more than the flat rate (long car commute, home office), you can lower your taxable income.

The assumptions behind the calculation

ItemMethod
ONSS13.07% of annual gross (white-collar). For a blue-collar worker: ~13.07% + 0.5-1% depending on the sector.
Professional expensesFlat rate 30%, capped at 5 930 €/year.
Personal income tax brackets25 % (0–16 320 €) · 40 % (16 320–28 800 €) · 45 % (28 800–49 840 €) · 50 % (above).
Tax-exempt allowance10 910 € base + progressive supplements for children. Imputed on the lowest brackets, not deducted from income.
Spouse without incomeMarital quotient: 30% of net income (capped at 13 460 €) is attributed to the spouse and taxed separately, with their own allowance.
Employment bonusLinear degressive: €272/month for gross ≤ €2,178, €0 at €3,320.
13th month & holiday payIncluded in the total annual gross before ONSS and personal income tax calculation.
Meal vouchersEmployer share (max €6.91/day) considered net of tax — which is the case in practice.
⚠️ What this calculation does not cover

The tool does not cover: specific deductions (service vouchers, childcare, regional mortgage loan), particular blue-collar vs white-collar contributions, municipal tax (additional 6-9%), specific tax regimes (researchers, expats), nor the withholding tax calculated at the joint committee level. For the exact figure to 0.1% accuracy, look at your payslip or use the official simulator from the Federal Public Service Finance. If you want to know how this net translates into a home loan, see your borrowing capacity.

🎯 Employee vs self-employed — who earns more net?

The guide compares the two statuses at equivalent income. Spoiler: the answer is not obvious.

Compare →
🕐 Last updated: May 2026 — Personal income tax brackets indexed. ±2-3% accuracy vs actual payslip.

Official sources

FPS Finance — Official simulator
Social security — Contributions
ONSS — Employer/employee contributions