How to use the calculator
- Gross monthly salary — your salary as it stands in December, before INSS and income tax. If you leave the job during the year, use the salary of your last month.
- Months worked this year — 12 if you were employed all year. Otherwise count the months, including every month in which you worked at least 15 days.
- Average monthly variable pay — overtime, commissions, night-shift premium or other pay that changes from month to month. Add up what you earned from January to November and divide by 11. Leave it at zero if your pay is fixed.
- Dependents — the dependents you declared to your employer for income tax.
- First installment — usually half of the 13th, paid without deductions. Choose Not paid yet if you will receive everything in December, or enter the amount if your employer paid a different advance.
The headline is the net 13th salary — both installments together, after INSS and income tax. The second card is the advance, the third is what the December payment brings after all deductions.
How the 13th salary is calculated
The 13th salary (gratificação natalina, popularly décimo terceiro) was created by Law 4,090 of 1962 and is guaranteed by article 7 of the Constitution. Its rules are now consolidated in Decree 10,854 of 2021 (articles 76 to 78), which replaced Decree 57,155 of 1965:
- One twelfth per month. The employee earns 1/12 of the pay owed in December for each month of service in the year. A fraction of 15 days or more counts as a full month; legal and justified absences are not deducted.
- Variable pay is included. For overtime, commissions and other variable amounts, the employer uses 1/11 of what was owed from January to November, then reviews the figure by January 10 with December included and pays any difference.
- Two installments. The advance — half of the previous month’s salary, or half of the proportional 13th for someone hired during the year — is paid between February and November, so by November 30 at the latest. If you ask for it in January, it comes with your vacation pay. The rest is due by December 20.
INSS on the 13th
The 13th counts for social security, but it is charged on its own: the progressive monthly table is applied to the whole gross 13th, separately from the December salary, and withheld from the final installment (Decree 3,048 of 1999, article 214). Nothing is deducted from the advance. The 2026 table (Portaria Interministerial MPS/MF nº 13 of 9 January 2026):
| Slice of the 13th (R$) | Rate |
|---|---|
| up to 1,621.00 | 7.5% |
| 1,621.01 to 2,902.84 | 9% |
| 2,902.85 to 4,354.27 | 12% |
| 4,354.28 to 8,475.55 | 14% |
Income tax on the 13th
Income tax on the 13th is withheld exclusively at source: it is calculated on the full amount, in the month the 13th is settled, separately from all other income, and there is no withholding on the advance (Law 8,134 of 1990, article 16). It does not mix with the tax on your December salary. The base is the gross 13th minus either the legal deductions — the INSS on the 13th plus R$ 189.59 per dependent, plus alimony or private pension where they apply — or the R$ 607.20 simplified monthly discount, whichever produces less tax. The Receita Federal’s rules allow the simplified discount on the 13th as well. The base then goes through the 2026 monthly table: exempt up to R$ 2,428.80, then 7.5%, 15%, 22.5% and 27.5% above R$ 4,664.68.
The 2026 reduction applies to the 13th. Law 15,270 of 2025 created the monthly reduction that cancels the tax on income up to R$ 5,000 and phases out at R$ 7,350, and its paragraph 3 says the reduction is also used for the tax charged exclusively at source on the 13th salary. Following the Receita Federal’s published examples, which measure the reduction on gross pay rather than on the tax base, the calculator measures it on the gross 13th:
- gross 13th up to R$ 5,000.00: the tax is reduced to zero;
- from R$ 5,000.01 to R$ 7,350.00: reduction = R$ 978.62 − 0.133145 × gross 13th;
- above R$ 7,350.00: no reduction.
Worked example: R$ 6,000 a month, all year
- Gross 13th: 6,000 × 12 ÷ 12 = R$ 6,000.00. The first installment, by November 30, is R$ 3,000.00, with no deductions.
- INSS on the whole 13th: 1,621.00 × 7.5% + 1,281.84 × 9% + 1,451.43 × 12% + 1,645.73 × 14% = R$ 641.51.
- Tax base: 6,000 − 641.51 = R$ 5,358.49 (the legal deduction beats the R$ 607.20 discount). Tax by the table: 5,358.49 × 27.5% − 908.73 = R$ 564.85.
- Reduction: 978.62 − 0.133145 × 6,000 = R$ 179.75, so IRRF = R$ 385.10.
- Second installment: 6,000 − 3,000 − 641.51 − 385.10 = R$ 1,973.39. Net 13th: R$ 4,973.39.
Net 13th salary at common salaries (2026, full year, no dependents)
| Monthly salary (R$) | 1st installment | INSS | IRRF | 2nd installment | Net 13th |
|---|---|---|---|---|---|
| 1,621.00 | 810.50 | 121.58 | 0.00 | 688.92 | 1,499.42 |
| 3,000.00 | 1,500.00 | 248.60 | 0.00 | 1,251.40 | 2,751.40 |
| 4,500.00 | 2,250.00 | 431.51 | 0.00 | 1,818.49 | 4,068.49 |
| 6,000.00 | 3,000.00 | 641.51 | 385.10 | 1,973.39 | 4,973.39 |
| 8,000.00 | 4,000.00 | 921.51 | 1,037.85 | 2,040.64 | 6,040.64 |
| 10,000.00 | 5,000.00 | 988.09 | 1,569.55 | 2,442.36 | 7,442.36 |
The second installment is always smaller than the first, because all the deductions come out of it.
FGTS and other details
- FGTS: the employer deposits 8% of each installment into your FGTS account by the 20th of the following month (Law 8,036 of 1990, article 15). It is not taken from your pay.
- Leaving the job: the proportional 13th is paid with the severance, except after dismissal for just cause.
- Unjustified absences can make a month fall below 15 days worked, so it no longer counts.
- This is an estimate. Alimony, private pension contributions, other payroll items or a collective agreement can change your figures — your payslip, your employer’s payroll department or an accountant have the final word.
For your regular monthly pay, use the Brazil net salary calculator; the same INSS and income tax tables apply.
Frequently asked questions
When is the 13th salary paid in 2026?
The first installment is paid between February and November, so by November 30, 2026 at the latest (or with your vacation, if you asked for it in January). The second installment is due by December 20, 2026.
Is INSS or income tax taken from the first installment?
No. The advance is paid in full. INSS and income tax are calculated on the whole 13th and taken from the second installment, which is why the December payment is smaller.
Does the R$ 5,000 income tax exemption apply to the 13th?
Yes. Law 15,270/2025 says the 2026 reduction also applies to the tax withheld on the 13th salary, which is taxed separately from your monthly pay. A 13th of up to R$ 5,000 pays no income tax; between R$ 5,000.01 and R$ 7,350 the tax is reduced partially.
I started working this year. Do I get a 13th salary?
Yes, a proportional one: 1/12 of your salary for each month worked, counting every month with 15 or more days of work. Someone hired on June 1 with a R$ 3,000 salary has 7 months by December and earns a gross 13th of 3,000 × 7 ÷ 12 = R$ 1,750. Hired on May 15 instead, May counts too (17 days), making 8 months.
Are overtime and commissions included?
Yes. Variable pay enters the 13th as a monthly average — the employer uses 1/11 of what you earned from January to November and adjusts it in January once December is known.
Last updated: October 15, 2026