What is net disposable income (NBI)?
Net disposable income (NBI) is the monthly income left after tax and contributions, plus tax credits and benefits. It is the basis for the capacity calculation for both child and spousal maintenance.
The NBI differs from your net salary: it also includes benefits such as the healthcare benefit and the child-related budget, and it is calculated over the full year, including the income tax assessment.
How do you calculate your NBI?
The calculation in five steps:
- Gross annual income — salary, benefit or taxable profit (self-employed).
- Income tax box 1 — using the 2026 tax brackets: 35.75% up to € 38,883, 37.56% up to € 78,426 and 49.50% above (the NBI table 2026 shows what this yields per income).
- Deduct tax credits — general tax credit (max. € 3,115), employed person's tax credit (max. € 5,685) and, where applicable, the income-dependent combination tax credit (IACK).
- Add benefits — healthcare benefit, child-related budget (incl. the single-parent supplement after a divorce), housing benefit.
- Divide by 12 — the monthly result is the NBI.
| Gross annual income | € 45,000 |
| Income tax (box 1) | – € 16,198 |
| General tax credit | + € 2,138 |
| Employed person's tax credit | + € 5,674 |
| Healthcare benefit | + € 0 (at this income) |
| Net annual income | € 36,614 |
| NBI per month | ± € 3,051 / month |
Illustrative. The actual amounts depend on your precise situation, deductions and benefits.
NBI for the self-employed
For the self-employed the NBI is calculated from the taxable profit after:
- Self-employed deduction (€ 1,200 in 2026)
- SME profit exemption (12.7% in 2026)
- Income tax on the remaining profit
- Any benefits
The NBI of a self-employed person fluctuates more than that of an employee. The court or mediator often uses an average over three years, so that a single good or bad year counts for less.
NBI with a benefit (unemployment, disability, social assistance)
With a benefit, the gross benefit amount is the starting point. Specific tax credits apply depending on the type of benefit. Alimentatie Inzicht calculates the NBI automatically in benefit situations too.
The child-related budget in the NBI
The child-related budget (including the single-parent supplement) counts towards the NBI of the caring parent. That raises that parent's capacity, and with it their share of the costs; it does not reduce the child's needs — a crucial part of the calculation that is often overlooked in practice.
Frequently asked questions
What is net disposable income (NBI)?
The NBI is the income left each month after tax and contributions, plus tax credits and benefits. It is the basis for the capacity calculation for maintenance.
Does the child-related budget count in the NBI?
Yes. The child-related budget (including the single-parent supplement) is added to the NBI of the caring parent. It does not reduce the child's needs — it raises that parent's capacity, and with it their share of the costs (Dutch Supreme Court, 9 October 2015, ECLI:NL:HR:2015:3011).
How does the NBI differ from net salary?
Net salary is what the employer pays out after payroll tax. The NBI is broader: it also includes benefits and is calculated on an annual basis, including the tax assessment and tax credits.
How is the NBI calculated for the self-employed?
From the taxable profit after the self-employed deduction and the SME profit exemption, the income tax on that and any benefits. Alimentatie Inzicht supports NBI calculations for the self-employed.