How the calculator works: 2026 methodology

Rounding and units

Social contributions, the health contribution and PPK payments are rounded to the nearest grosz (the Polish cent), each one separately. The taxable base and the tax advance are rounded to the whole złoty, as on a Polish payroll: amounts under 50 groszy are dropped and 50 groszy or more round up. On screen we show amounts without groszy, but all calculations run in groszy, so the breakdown lines can differ from the net figure by one złoty.

Employment contract: month by month

For each of the twelve months the engine runs the same sequence, carrying three running totals from month to month: gross subject to the contribution cap, income exempted under the youth relief, and the taxable base.

1. Pension and disability base = the smaller of this month's gross and what is left of the PLN 282,600 cap after previous months. Pension = base × 9.76 %, disability = base × 1.5 %. Sickness = full gross × 2.45 %, as the cap does not apply to it.
2. Health contribution = 9 % × (gross − social contributions), but no more than the tax advance computed under the rules in force on 31 December 2021: 17 % × rounded (gross − contributions − costs) − PLN 43.76. This cap comes from art. 83(1), (2a) and (2b) of the healthcare act. Under the youth relief we compute it as if the income were not exempt (para. 2a). In practice it only bites on very low pay.
3. Taxable income = gross + the employer's PPK payment, which counts as the employee's income. Under the youth relief the exempt part is removed until total exemptions for the year reach PLN 85,528; social contributions are then deducted in proportion to the taxable part.
4. Deductible costs = PLN 250 a month, or PLN 300 for commuters, capped at taxable income. With creative work costs: 50 % of the copyright share of gross after the contributions attributable to it, up to PLN 120,000 a year in total.
5. Taxable base = (taxable income − deductible contributions − costs), rounded to the złoty.
6. PIT advance = the part of the base within PLN 120,000 cumulatively × 12 % + any excess × 32 % − PLN 300 if PIT-2 is filed, rounded to the złoty and never below zero. The threshold is checked against the base accumulated with the same payer since January, as art. 32 of the PIT Act requires.
7. Net = gross − social contributions − health contribution − tax advance − employee PPK (2 % of gross, taken after tax).
8. Employer cost = gross + pension 9.76 % and disability 6.5 % on the base from step 1 + accident 1.67 % + Labour Fund 1 % + Solidarity Fund 1.45 % + FGŚP 0.1 % on full gross + employer PPK.

Worked example at the PLN 4,806 minimum wage: social contributions PLN 658.91, health PLN 373.24, taxable base PLN 3,897, tax advance PLN 168 after the PLN 300 reduction, net PLN 3,605.85, or PLN 3,606 rounded. The employer's cost is PLN 5,790.28.

The net-to-gross calculator runs the same engine backwards by bisection: it searches for the smallest gross at which first-month net reaches your target, to the grosz. There is no separate reverse formula that could drift away from the forward calculation.

Mandate contract (umowa zlecenie)

Pension 9.76 % and disability 1.5 % on gross; sickness 2.45 % only if voluntary cover is ticked. A pupil or student under 26 pays no social contributions, and the calculator then also assumes no health contribution on the contract. The health contribution is 9 % of gross after contributions, with the same “2021” cap as on employment, computed with 20 % costs but without subtracting PLN 43.76.

When the contract is worth no more than PLN 200, tax is a flat 12 % of the whole amount, with no costs and no PIT-2, and the health contribution is not capped. Above that, costs are 20 % of gross after contributions (or 50 % on the copyright share), the base is rounded to the złoty, and the advance is 12 % less PLN 300 if you filed PIT-2 with the client. Under the youth relief the advance is zero. On the client's side we add pension 9.76 %, disability 6.5 % and accident 1.67 %, plus the Labour Fund, Solidarity Fund and FGŚP only when the contract pays at least the minimum wage.

Specific-work contract (umowa o dzieło)

The model charges no social or health contributions. Up to PLN 200, tax is 12 % of revenue. Above that: costs of 20 % of revenue, or 50 % when copyright is transferred, base rounded to the złoty, advance 12 % less PLN 300 with PIT-2. On a PLN 1,000 contract that gives PLN 96 of tax, and PLN 60 with creative work costs.

B2B: monthly average of the year

Self-employment is computed for the year and divided by twelve, because the health contribution, the tax threshold and the deduction limits are annual. Self-employed social contributions use a base of PLN 5,652 (full ZUS) or PLN 1,441.80 (preferential): pension 19.52 %, disability 8 %, accident 1.67 %, sickness 2.45 % only with voluntary cover, and Labour plus Solidarity Fund 2.45 % only on full ZUS. That gives PLN 1,926.76 a month on full ZUS with sickness cover and PLN 456.18 on preferential. Under the start-up relief social contributions are zero.

• Tax scale: health 9 % of income (revenue − costs − Labour Fund − social contributions), at least PLN 432.54 a month; tax 12 % up to PLN 120,000 of yearly base and 32 % above, less the PLN 3,600 tax reduction.
• Flat tax: health 4.9 % of the same income, at least PLN 432.54; health paid reduces the base by up to PLN 14,100 a year; tax 19 %.
• Ryczałt: fixed health amount by yearly revenue: PLN 498.35 up to PLN 60,000, PLN 830.58 up to PLN 300,000, PLN 1,495.04 above; half the health paid and the social contributions reduce revenue; tax at the rate chosen for your industry.

B2B net = revenue − costs − social contributions − Labour Fund − health − tax. VAT is left out: enter invoice revenue net of VAT.

Sick pay and overtime

The sick-pay base is monthly gross less the 13.71 % employee social contributions; the daily rate = base ÷ 30 × 80 %. No social contributions are charged on the benefit, while the health contribution is computed on the full benefit. For overtime, the hourly rate = gross ÷ hours worked in the month, and the supplement is 50 % or 100 % of that rate, under art. 151¹ of the Labour Code.

What the calculator does not cover

We would rather say plainly where the model stops than claim precision it does not have. Results can differ from reality in these situations:

• Several employers or contracts at once: each contract is computed alone, with no shared contribution cap, shared threshold or PIT-2 split.
• Voluntary contributions, or PPK with additional payments or a reduced employee rate: basic rates are assumed.
• The accident contribution is set at 1.67 %, though your employer's rate can be anywhere from 0.4 % to 8.12 %; this only affects employer cost.
• Labour Fund and Solidarity Fund exemptions for workers aged 55+ and 60+, and the bridging-pension (FEP) contribution, are not modelled.
• The return relief, the 4+ family relief and the working-senior relief are not available; only the youth relief is.
• On zlecenie and dzieło the 12 % rate is applied; the second bracket and interaction with employment income are left to your annual return.
• B2B is a yearly average: the PLN 432.54 minimum health contribution is applied to all twelve months, although January's is PLN 314.96; month-to-month income swings, “small ZUS plus” and the solidarity levy are not modelled.
• Non-tax deductions such as union dues, group insurance or garnishments are unknown to the calculator.

How we test the engine

The engine has 24 automated tests (vitest), run before every release. Each compares a result with a figure worked out by hand or published by an institution. A few examples from the test file:

• Minimum wage PLN 4,806: contributions PLN 658.91, health PLN 373.24, base PLN 3,897, advance PLN 168, net PLN 3,606.
• PLN 5,000 gross: base PLN 4,065, advance PLN 188, because 12 % of the base minus PLN 300 leaves an amount with groszy that rounds up to the złoty.
• Full self-employed ZUS: PLN 1,926.76 with sickness cover and PLN 1,788.29 without, identical to the grosz to the figures ZUS publishes; preferential: PLN 456.18 and PLN 420.86.
• Ryczałt on PLN 15,000 monthly revenue: health PLN 830.58, the band up to PLN 300,000.
• PLN 25,000 gross: cap reached in December, with that month's pension contribution charged only on the remainder up to the cap; December net PLN 14,264.
• PLN 12,000 gross: the second bracket only appears in December.
• Specific-work contract for PLN 1,000: PLN 96 of tax, PLN 60 with creative work costs; a PLN 200 contract: flat-rate tax.

The remaining tests cover PIT-2, the PLN 300 commuter costs, the youth relief up to PLN 85,528, PPK, employer cost, the net-to-gross inversion, students on zlecenie, the minimum health contribution on flat tax, the start-up relief, sick pay and overtime supplements. If you find a case where the calculator disagrees with your payroll, tell us: every confirmed error becomes a new test.

Parameters and their sources

This table is generated from the parameter file. Full titles of the acts, with links, are in the sources section at the bottom of the page.