Number format: this calculator uses German notation throughout — a comma is the decimal separator and a dot groups thousands. “1.234,56” means one thousand two hundred thirty-four euros and fifty-six cents. The figures come from German tax law, so they are shown the way German authorities write them.
Net to gross
The inverse of the net calculation — which gross salary produces a desired net figure?
In plain language
The usual question is: “I earn X gross — what is left?” This one turns it round: “I need X net — what has to be in the contract?” That is the question you actually have in a salary negotiation. There is no formula for it, because the tax scale is not a straight line. So the calculator tries gross figures and feels its way towards the target — using the same verified calculation, only the other way round.
In detail
The forward calculation from gross to net cannot be inverted in closed form: the scale of § 32a EStG is defined piecewise, the official program rounds to whole euros, and the social security contributions have assessment ceilings with kinks. Rather than write a second, approximate rule — which would diverge from the first — the calculator searches numerically: it evaluates the verified forward calculation at candidate gross figures and halves the interval until the net figure matches. The number of steps appears in the result; it is the proof of convergence. Because rounding is to whole euros, not every target net figure is exactly reachable; in that case the calculator names the nearest reachable value instead of rounding silently. The search starts above the marginal employment threshold — below it the minijob rules apply, with their own logic.
Worked example
Target net pay 2.500,00 € a month, tax class 1, North Rhine-Westphalia, no church tax: 3.804,78 € gross is required. Found in 19 steps of interval halving, and the target is hit exactly. Every euro of net pay needs roughly 1,52 € gross here — and that factor rises with the salary, because the scale is progressive.
In brief
No formula exists; the gross is searched numerically on the same verified forward calculation, to the cent.
Legal basis: § 39b EStG, BMF Programmablaufplan 2026 · as at 2026