How we calculate
Total 13th = 1/12 of salary × months worked. First installment (by Nov 30) is half, tax-free. Second installment (by Dec 20) has INSS/IRRF deducted from the total.
Formula used
Total = (salary ÷ 12) × months worked. First installment = total ÷ 2. Second = total ÷ 2 − INSS − IRRF.
13º = (salário ÷ 12) × meses trabalhados, com INSS/IRRF descontados na 2ª parcela
Practical example
An employee earning R$ 3,000 who worked all 12 months receives R$ 3,000 total, split into two installments.
How to interpret the result
The second installment is always smaller since it carries all the tax deductions.
Limitations
Does not account for leaves of absence or collective bargaining specifics. Tables used may be outdated.