How the Luxembourg indépendant calculator is verified

Inputs

InputFieldType
Annual profit after expenses (EUR)annualProfitnumber

The formula

Each derived value below is computed by the Valem engine from the expression shown, in this order. Nothing else runs — there is no hidden code path.

Derived valueFieldFormula (JSONata)
Income tax (class 1)baseTax($t := annualProfit; $round(0.08 * $max([0, $min([$t, 15400]) - 13200]) + 0.09 * $max([0, $min([$t, 17600]) - 15400]) + 0.10 * $max([0, $min([$t, 19800]) - 17600]) + 0.11 * $max([0, $min([$t, 22050]) - 19800]) + 0.12 * $max([0, $min([$t, 24250]) - 22050]) + 0.14 * $max([0, $min([$t, 26550]) - 24250]) + 0.16 * $max([0, $min([$t, 28800]) - 26550]) + 0.18 * $max([0, $min([$t, 31100]) - 28800]) + 0.20 * $max([0, $min([$t, 33400]) - 31100]) + 0.22 * $max([0, $min([$t, 35700]) - 33400]) + 0.24 * $max([0, $min([$t, 38000]) - 35700]) + 0.26 * $max([0, $min([$t, 40300]) - 38000]) + 0.28 * $max([0, $min([$t, 42600]) - 40300]) + 0.30 * $max([0, $min([$t, 44900]) - 42600]) + 0.32 * $max([0, $min([$t, 47200]) - 44900]) + 0.34 * $max([0, $min([$t, 49500]) - 47200]) + 0.36 * $max([0, $min([$t, 51750]) - 49500]) + 0.38 * $max([0, $min([$t, 54050]) - 51750]) + 0.39 * $max([0, $min([$t, 117450]) - 54050]) + 0.40 * $max([0, $min([$t, 176150]) - 117450]) + 0.41 * $max([0, $min([$t, 234850]) - 176150]) + 0.42 * $max([0, $t - 234850]), 2))
Employment fund surchargeemploymentFund$round(baseTax * (annualProfit > $const.employmentFundThreshold ? $const.employmentFundHighRate : $const.employmentFundRate), 2)
Income after tax (before contributions)incomeAfterTax$round($max([0, annualProfit - baseTax - employmentFund]), 2)

Rates and thresholds

The expressions above read these as $const. They are the figures the annual refresh replaces, so they live as data rather than being written into the formulas — which is what makes a year-on-year change a one-line diff instead of an edit to arithmetic.

ConstantValue
employmentFundRate0.07
employmentFundHighRate0.09
employmentFundThreshold150000

Test vectors (3)

Every case is executed against this model on each build, by the Java engine and independently by a JavaScript one. A mismatch of a single cent fails the build, so the page cannot ship advertising a figure the model no longer produces.

Case 1 — 70,000 EUR profit — a typical full-time indépendant

given annualProfit70000
expect baseTax15074
expect employmentFund1055.18
expect incomeAfterTax53870.82

Case 2 — 25,000 EUR — part-time

given annualProfit25000
expect baseTax1210.5
expect employmentFund84.74
expect incomeAfterTax23704.76

Case 3 — 200,000 EUR — above the 9% employment fund threshold

given annualProfit200000
expect baseTax66838
expect employmentFund6015.42
expect incomeAfterTax127146.58

Sources

Check it yourself — and reuse it

The whole model as JSON — inputs, outputs, formulas, vectors and sources in one re-runnable document.

This model is published under CC BY 4.0: use it, adapt it, build on it, with attribution. The licence covers the model — the expression of each rule and the arrangement of the catalog. The rates and thresholds are law, and nobody licenses those; the sources above are where they come from.

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