NZ Child Support Calculator

IRD uses an administrative assessment formula. Each parent's taxable income is reduced by a living allowance, then income shares are calculated. The cost of children is looked up from IRD tables based on combined income and the number/ages of children. Care time offsets are applied based on nights of care. The parent with the higher income share and lower care time typically pays the difference.

The living allowance is a flat amount deducted from each parent's income before calculating child support: $30,557 for 2026-27 (from 1 April 2026), $29,909 for 2025-26, and $28,612 for 2024-25. Parents receiving a supported living payment get a higher allowance ($34,252 for 2026-27). A parent's own dependent children are recognised separately through a dependent child allowance based on the IRD child expenditure tables.

Shared care reduces the amount payable. If you have the children less than 28% of nights (about 102 nights), there is no care cost offset. At 28-34% you receive a 24% offset. From 35-47% it increases gradually. At 48-52% (substantially shared care) each parent gets a 50% cost offset. Over 72% care means a 100% offset — the other parent pays you.

IRD sets a minimum annual rate of child support. Even if the formula produces a very low figure, the paying parent is still required to pay the minimum — $1,211 per year for 2026-27 ($1,175 for 2025-26, $1,150 for 2024-25), roughly $23 per week.

Yes. The IRD cost of children tables have different rates for children aged 0-12 and children aged 13+. Older children are considered more expensive to support, so child support may increase when a child turns 13.

Yes. You can apply to IRD for an administrative review if your circumstances have changed significantly — for example, income changes, changes in care arrangements, or special expenses. Both parents can request a review.

No. Child support payments received are not taxable income for the receiving parent. Likewise, child support payments made are not tax-deductible for the paying parent.

If one parent has zero income, their adjusted income is zero and their income share is 0%. The entire income share belongs to the other parent. However, the parent with zero income may still be assessed at a minimum amount if they are the liable parent.