Belgium taxes a salary in three layers and takes social security off before any of them. The FEDERAL scale runs in five brackets from 25% to 50%, with a zero-rate band that varies with household composition. On top sits a REGIONAL additional tax, which the regions have been able to set for themselves since the Sixth State Reform. On top of that sits a COMMUNAL surcharge set by the municipality, 7% in the Brussels capital region. Only after all three do you have a net.
The federal ladder
The European Commission's Taxes in Europe database records the Belgian personal income tax as five brackets applying to aggregate annual income before allowances, at 25%, 30%, 40%, 45% and 50%. The thresholds are indexed every year, so a figure quoted from an old article is wrong by the indexation. What does not move is the shape: Belgium reaches its top rate at a much lower income than the UK does, which is the single most important thing for a UK reader to understand about a Belgian offer.
The zero-rate band, which is not a personal allowance
A global zero-rate band, varying according to household composition, is exempt from tax. It starts as a basic band for each spouse, is increased for dependants and for certain family situations, and where one spouse's band exceeds their own income the balance transfers to the other. It is calculated from the bottom up, so it exempts the lowest slice of income rather than reducing the top. The practical effect is a UK-like allowance that moves with your family rather than a fixed figure.
The two surcharges
The regions levy a regional additional tax on the federal tax, and the municipalities levy a communal surcharge as a percentage of it: in the capital city the rate recorded is 7%, of which 6% goes to the municipalities and 1% to the Brussels agglomeration. Both are charged on the TAX rather than on the income, so they multiply whatever the federal calculation produced. A calculator that does not ask which commune you live in is leaving that multiplier out.
Social security first, which is why gross looks worse than it is
Employee social security is deducted from the gross before any income tax is worked out, and the taxable base is the gross less that contribution. Employers pay a substantially larger contribution on top, which never appears on the payslip. Belgium's combined wedge between what an employer spends and what an employee receives is among the largest in Europe, which is worth knowing before comparing a Belgian gross with a UK one: the Belgian number is further from the employer's cost and further from your net at both ends.
What this page does not reproduce, and why
The indexed bracket thresholds and the current-year zero-rate band. On 17 September 2026 the Belgian federal finance administration's own rate pages, at fin.belgium.be and finance.belgium.be, answered this site's read with a CAPTCHA rather than with content, and the same happened on belgium.be. Rather than reproduce figures from somewhere that is not the source, this page gives the structure from the European Commission's database and links the official pages for the numbers. If you need the exact thresholds for a decision, the FPS Finance calculator is the one to use.
Questions people ask about belgium tax calculator
What are Belgian income tax rates?
Five brackets at 25%, 30%, 40%, 45% and 50% on aggregate annual income before allowances, with the thresholds indexed each year, plus a regional additional tax and a communal surcharge on the tax.
Is there a Belgian personal allowance?
There is a zero-rate band that varies with household composition, calculated from the bottom up, increased for dependants and transferable between spouses where one band exceeds that spouse's income.
What is the communal surcharge?
A percentage the municipality charges on your income tax rather than on your income. The rate recorded for the capital city is 7%, 6% to the municipalities and 1% to the Brussels agglomeration.
Why does this page not list the current thresholds?
Because the Belgian administration's own rate pages answered this site's read with a CAPTCHA on 17 September 2026. The structure here comes from the European Commission's tax database, and the official pages are linked for the figures.