13th Salary Calculator
Calculate the Brazilian 13th salary, proportional to months worked, with INSS and income-tax deductions on the second installment.
- Proportional 13th
- 1st installment (by Nov 30)
- INSS on 13th
- IRRF on 13th
- 2nd installment (by Dec 20)
- Net total
How does the 13th salary work?
The 13th is an annual bonus equal to 1/12 of the salary per month worked. Payment comes in two installments: the first arrives by November 30 with no deductions; the second, by December 20, already has INSS and IRRF taken out.
Deductions fall on the full value of the 13th rather than on each separate installment. That is what makes the second installment smaller.
It is a simplified calculation, and some companies follow collective bargaining agreements with their own rules.
How the Brazilian 13th salary works
The décimo terceiro salário, usually translated as "Christmas bonus", is an extra month of pay that employers must hand out under Law 4.090/1962, a right the Federal Constitution also guarantees. It reaches every CLT employee. To work out the proportional amount, use 13º = (gross salary / 12) · months worked; any month in which you put in at least 15 days counts in full. So someone on R$ 3,000 who worked 7 full months during the year is owed 3000 / 12 · 7 = R$ 1,750.
Habitual variable pay goes into the base too. Regular overtime, the night-shift premium, hazard pay (insalubridade/periculosidade) and sales commissions all get averaged in, while one-off bonuses and reimbursements stay out. When income varies from month to month, the law says to take the arithmetic mean of what was received across the year.
Two installments, taxes only on the second
Payment comes in two parts. The first installment, half of the gross 13th, has to land between February 1 and November 30. Plenty of employers pay it in late November, or fold it into the worker's vacation when the employee asks. Nothing is taken out of it: no INSS or IRRF deduction applies. The second installment is due by December 20, and this is where INSS and IRRF are calculated on the full gross 13th and pulled out in full. That is why the second installment always comes in below the first.
INSS on the 13th is figured separately from your monthly salary, so the progressive brackets run again on the 13th value by itself rather than piling on top of the December paycheck. Take a R$ 3,000 13th: INSS applies the standard 2024 brackets (7.5% up to R$ 1,412, then 9% on whatever is left), which works out to about R$ 248. IRRF then follows the usual monthly table once you subtract INSS and the dependent deductions of R$ 189.59 per dependent in 2024.
FAQ
What happens if I am fired before December? Your proportional 13th comes through in the severance pay (rescisão), counted on the full months you worked that year. The one exception is dismissal for just cause, which wipes out the right to the proportional 13th.
Does FGTS apply to the 13th? Yes. The employer also deposits 8% of the 13th into FGTS, covering both installments in the months each one is paid.
Can I receive the first installment together with vacation pay? You can. Put in a formal request between January and the end of February of that same year, and the employer is obliged to pay the first installment along with your vacation. Skip that, and the November 30 deadline is what governs.
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Calculate your 13th-month salary
The 13th-month salary is proportional to the months worked in the year, and the second instalment still comes with deductions. That's why the net amount often surprises people, ending up smaller than expected. This calculator shows how much you have to receive, already accounting for the months and the deductions.
It works out the amount proportional to the months worked and applies the social-security and income-tax deductions that fall on the second instalment. Seeing the detailed math makes it clear why the first instalment, paid without deductions, comes out larger than the second, and lets you plan year-end finances with the right number.
The calculation runs in the browser and stores none of your data. A practical reference for checking the 13th salary and organising December's budget.