Methodology and sources

How we choose sources

Every figure used by the calculators comes from an official source: the contribution table published by INSS (Brazil's social security institute), the tax tables of the Receita Federal (the federal tax authority) and the text of the laws on the Planalto website (the CLT labour code, the Constitution, the FGTS law, Lei 8.212/1991, Lei Complementar 123/2006 and others). We do not rely on other calculator sites, blogs or news reports; when a rule appears in the press before it is officially published, we wait for the official text. The table below lists each parameter with its value, effective date and source link.

How often we update

We update whenever a new ordinance (portaria), law or table is published — typically in January, with the new minimum wage and the adjusted INSS brackets. On top of that, the tables are reviewed at least once a month, even when no change has been announced. The date of the latest review is shown with the table.

Rounding rules

• Employee INSS is worked out bracket by bracket, and the amount for each bracket is rounded to the cent before adding them up — the same way it appears in a breakdown of the progressive table.
• All rounding is to two decimal places, with half a cent rounded away from zero (R$0.005 becomes R$0.01).
• Income tax is calculated on the already-rounded base, and the Lei 15.270/2025 reduction is applied to taxable income, as in the Receita Federal's worked examples.

What we deliberately leave out

The calculators follow the general rules of the law and leave out what depends on each case:

• collective agreements (minimum wages for a trade, higher premiums, sector benefits);
• absences, leave and contract suspensions;
• in the severance calculator, averages of overtime, commissions and other variable pay, and fixed-term or probationary contracts;
• double payment of overdue vacation not granted on time (CLT art. 137): the result shows the single amount and flags it;
• state and municipal rules beyond the fixed MEI amounts.

That is why every result is an estimate. The employer's payroll and an accountant give the official figure.

The income tax reduction on the 13th salary

The Lei 15.270/2025 reduction also applies to the tax withheld exclusively at source on the 13º salário (13th salary), under art. 3º-A, §3º, of Lei 9.250/1995, added by Lei 15.270/2025. Both the 13th salary calculator and the pro-rata 13th in the severance calculator work out the reduction on the gross 13th; up to R$5,000.00, the withholding on the 13th is zero.

Review of 13 November 2026

On 13 November 2026 we re-checked the source of every parameter. When the Planalto website (the Presidency’s official law portal) was unavailable, we used the legal texts published by the Senado Federal. One value is still not confirmed against an official text: the per-day IOF percentages (Annex to Decreto 6.306/2007), flagged as unverified in the table below. The 11% INSS on pró-labore (owners’ pay) was checked against Lei 8.212/1991 (art. 30 §4) and Lei 10.666/2003 (art. 4).

How to report an error

If a result does not match your payslip or a table looks out of date, write to hello@canivetotool.com with the simulation link (the “Copy simulation link” button) or the values you entered, the amount you expected and, if possible, the source. More on the contact page.