B2B calculator 2026
Enter the net amount you invoice and your business costs. See what you keep per month and for the whole year under the tax scale, the flat tax and the ryczałt, with ZUS, the health contribution and PIT. No sign-up.
Law as of 21 October 2026.
Inputs
Without VAT. If you invoice in euro, convert to złoty.
Net, for example hardware, software, accounting. Under the ryczałt costs do not lower the tax.
Base of 60% of the forecast average wage.
The rate depends on the type of service (art. 12 ust. 1 of the Lump-sum Tax Act). Check your PKWiU code.
Result
Take-home per month, averaged over the year
- Tax scale9799,91 zł
- Flat tax9791,92 zł
- Ryczałt 12%10 328,96 zł
With these inputs the most is left under: Ryczałt 12%, 10 328,96 zł a month.
We calculate the whole year and divide by 12. Under the scale, income above 120,000 zł is taxed at 32%, so advances later in the year are higher than the average.
The same revenue and costs every month, one ZUS stage for the whole year, no other income, reliefs or joint filing with a spouse.
Forms of taxation compared for the year
| Per year | Tax scale | Flat tax | Ryczałt 12% |
|---|---|---|---|
| Revenue | 180 000,00 zł | 180 000,00 zł | 180 000,00 zł |
| Costs | 6000,00 zł | 6000,00 zł | 6000,00 zł |
| ZUS social contributions | 21 459,48 zł | 21 459,48 zł | 21 459,48 zł |
| Health contribution | 13 728,65 zł | 7474,49 zł | 9966,96 zł |
| of which deducted from income or revenue | 0,00 zł | 7474,49 zł | 4983,48 zł |
| PIT | 21 213,00 zł | 27 563,00 zł | 18 626,00 zł |
| Taxes and contributions | 56 401,13 zł | 56 496,97 zł | 50 052,44 zł |
| Take-home for the year | 117 598,87 zł | 117 503,03 zł | 123 947,56 zł |
| Take-home per month (average) | 9799,91 zł | 9791,92 zł | 10 328,96 zł |
Parameters and sources
- Minimum wage4806,00 złDz.U. 2025 poz. 1242
- Full ZUS base (60% of the forecast average wage)5652,00 złM.P. 2025 poz. 1206
- Preferential ZUS base (30% of the minimum wage)1441,80 złart. 18a, Social Insurance System Act
- Mały ZUS Plus: base range1441,80 zł – 5652,00 złart. 18c, Social Insurance System Act
- Rates: pension, disability, sickness, accident, FP and FS19.52% / 8% / 2.45% / 1.67% / 2.45%art. 22, Social Insurance System Act; art. 259, Labour Market Act
- Health: scale, flat tax9% / 4.9%art. 79, 79a and 81, Health Care Benefits Act
- Minimum health contribution under the scale and flat tax, February 2026 to January 2027432,54 zł (January 2026: 314,96 zł)art. 79, 79a and 81, Health Care Benefits Act
- Health under the ryczałt: revenue up to 60,000 zł, up to 300,000 zł, above498,35 zł / 830,58 zł / 1495,04 złart. 81 ust. 2e–2g, M.P. 2026 poz. 117
- Health contribution deductionflat tax up to 14 100,00 zł a year, ryczałt 50%M.P. 2025 poz. 1274
- Tax scale12% and 32% above 120,000 zł, 3,600 zł tax-reducing amountart. 27 ust. 1, PIT Act
- Flat tax19%art. 30c, PIT Act
- Solidarity levy4% of income above 1,000,000 złart. 30h, PIT Act
How we calculate
1. The whole year, not one month
We multiply the invoice and costs by 12 and calculate the year as in the annual return. The monthly amount is the average. Under the scale, income above 120,000 zł is taxed at 32%, so advances at the end of the year are higher than in January.
2. ZUS social contributions
They depend on the stage: the start-up relief means 6 months without social contributions, preferential ZUS a base of 1,441.80 zł for 24 months, Mały ZUS Plus a base from last year's income, and full ZUS a base of 5,652 zł (art. 18a, 18c and 22 of the Social Insurance System Act). Full ZUS without sickness insurance is 1,788.29 zł a month.
3. Health contribution
9% of income under the scale and 4.9% under the flat tax, at least 432.54 zł a month in both cases. Under the ryczałt 498.35 zł, 830.58 zł or 1,495.04 zł depending on annual revenue (art. 79a and 81 of the Health Care Benefits Act). Under the flat tax you deduct up to 14,100 zł a year, under the ryczałt half of what you paid, under the scale nothing.
4. PIT
Scale: 12% less the 3,600 zł tax-reducing amount, and 32% on income above 120,000 zł (art. 27 of the PIT Act). Flat tax: 19% from the first złoty (art. 30c). Ryczałt: your rate on revenue, with no deduction for costs (art. 12 of the Lump-sum Tax Act). On income above 1,000,000 zł the scale and flat tax add a 4% solidarity levy (art. 30h).
5. Take-home
Revenue less costs, social contributions, health contribution, PIT and the levy. Under the result we list every parameter with its legal basis.
What the calculator leaves out
- PIT reliefs and deductions, such as for children, IKZE and donations, joint filing with a spouse and other income, for example from employment.
- A change of ZUS stage during the year, such as the end of the start-up relief after 6 months. Calculate both stages separately.
- The 8.5% and 12.5% above 100,000 zł rates of art. 12 ust. 1 pkt 4 of the Lump-sum Tax Act (including rental and accommodation) and several ryczałt rates at once.
- IP Box, the tax card and ZUS contribution holidays.
- The Labour Fund exemption for women from 55 and men from 60.
- VAT: you enter net amounts. If you are VAT-exempt, enter the whole invoice.
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Frequently asked questions
How much do I keep from 15,000 zł net on B2B in 2026?
With 500 zł of monthly costs and full ZUS without sickness insurance, on average 9,799.91 zł a month under the scale, 9,791.92 zł under the flat tax and 10,328.96 zł under the 12% ryczałt. The differences come mostly from the health contribution and the 120,000 zł threshold on the scale.
Scale, flat tax or ryczałt on B2B: what does the result depend on?
On income, costs and the ryczałt rate. With full ZUS in 2026 the flat tax leaves more than the scale only from about 174,600 zł of annual income, because the scale has the tax-reducing amount and the flat tax a lower health contribution. The ryczałt gains when costs are low, since they do not reduce the tax. The tax form comparison shows the exact thresholds for your figures.
How much is ZUS on B2B in 2026?
For the first 6 months with the start-up relief you pay no social contributions. Then for 24 months preferential ZUS: 420.86 zł a month, 456.18 zł with sickness insurance. Full ZUS is 1,788.29 zł, 1,926.76 zł with sickness insurance. With revenue up to 120,000 zł last year you can pay Mały ZUS Plus on half your average monthly income, on a base between 1,441.80 zł and 5,652 zł. The health contribution always comes on top.
How much is the health contribution on B2B in 2026?
9% under the scale and 4.9% under the flat tax, of income less social contributions, at least 432.54 zł a month from February 2026. Under the ryczałt the amount depends on revenue in the year: 498.35 zł up to 60,000 zł, 830.58 zł up to 300,000 zł and 1,495.04 zł above.
Why is the result an average over the year?
Because PIT and the health contribution are settled annually. Under the scale, advances rise to 32% once income passes 120,000 zł, and the health contribution under the scale and flat tax is trued up in the annual reconciliation. A single month, such as January, overstates the result for higher earners.
Should I enter the invoice net or gross?
Net, without VAT. The VAT on the invoice goes to the tax office, so it is not your revenue. If you are VAT-exempt, enter the whole invoice amount.
Can I use the flat tax or ryczałt on B2B for my former employer?
Not if you do the same work you did as their employee this year. For the ryczałt the previous year counts too (art. 9a ust. 3 of the PIT Act, art. 8 ust. 2 of the Lump-sum Tax Act). The scale remains.
The calculator is for information only and is not tax advice. Calculations run in your browser; we store nothing.