Documented income of R$4,000, 1 child, 20%
- Input
- 20% × R$ 4.000
- Expected output
- R$ 800/mês
Within the observed 15% to 20% range for one child, over the chosen base (gross or net).
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how to calculate child support
There is no single formula answering "how do you calculate child support", because Brazilian law does not fix one. What exists is a balance (the child's needs versus the paying parent's ability) and a forensic practice that tends to fall between 15% and 30% of income per child, always decided case by case. This estimator shows all three bases used in practice side by side, so you can arrive at a hearing or negotiation with concrete numbers.
Within the observed 15% to 20% range for one child, over the chosen base (gross or net).
The most common path when there is no pay stub to prove income.
No. The Civil Code (articles 1,694 and 1,695) only sets out the needs of the child versus the ability of the paying parent, with no percentage table. The 15% to 30%-or-more ranges that circulate online summarize what forensic practice tends to observe, not a rule written into law, the final percentage is always a judge's decision, case by case, based on proof of income and real expenses.
No. No Brazilian court or law publishes an official calculator, precisely because there is no percentage table fixed by law. Tools like this one simulate orientative ranges based on what forensic practice tends to observe.
No, it is an estimation tool meant to organize your numbers before a hearing or negotiation, not a court filing. The generated calculation summary can help organize arguments, but proof of income and expenses needs to come from real documents filed in the case.
Brazilian law has no legal table fixing a child support percentage. The result below is an orientative range based on what forensic practice tends to observe, never "the amount owed". The real value is decided by a judge, case by case, based on the needs of the child versus the ability of the paying parent (Civil Code, articles 1,694 and 1,695).
The result of the selected calculation base, already with the custody adjustment applied. It is an estimate, not the amount a judge will necessarily set.
30% of gross vs. 30% of net: a difference of R$ 74,58 per month
Percentage range observed in forensic practice for 1 child: 15% to 20%
An illustrative range from forensic practice, not a legal table. Allocated across the children in this case when there are dependents from other relationships.
Range suggested by the balance: R$ 751,40 to R$ 751,40
Reference minimum wage: R$ 1.621,00 (Portaria Interministerial MPS/MF nº 13/2026)
Calculation Summary, Child Support Simulation ============================================= Gross monthly income: R$ 3.000,00 Net monthly income: R$ 2.751,40 30% of gross (R$ 900,00) vs. 30% of net (R$ 825,42): a difference of R$ 74,58 13th salary: R$ 0,00 Vacation pay + constitutional third: R$ 0,00 Deposited FGTS: - Habitual overtime: - Profit sharing (PLR): - Expanded base (income + included items): R$ 3.000,00 Total children of the paying parent (all relationships): 1 Suggested percentage range for this case: 15% to 20% Amount from the chosen calculation base: R$ 600,00 Final estimated amount: R$ 600,00 Total child expenses (balance panel): R$ 2.050,00 Estimated available ability of the paying parent (balance panel): R$ 751,40 Range suggested by the needs-versus-ability balance: R$ 751,40 to R$ 751,40 Legal basis: Civil Code, articles 1,694 and 1,695. There is no legal percentage table; the final amount depends on a case-by-case court decision. Simulation generated on 31/08/2026 by jkit.tools, orientative use only, does not replace legal analysis of the actual case.
Considering the needs of the child versus the ability of the paying parent (Civil Code, articles 1,694 and 1,695), it is requested that child support be set on behalf of 1 child, estimated in a range of 15% to 20% of the paying parent's Gross income income, which in this simulation corresponds to approximately R$ 600,00 per month, an amount subject to proof of income and expenses in the case record.
This estimator helps you arrive at a starting figure before any decision exists. If support has already been set (by agreement or court order) and installments are overdue, use the Support Arrears Calculator to work out the collection amount, with interest and monetary correction.
All the calculation runs in your browser. The data you enter (income, expenses, number of children) is never sent to any server or stored anywhere.