Shared Parenting and the 40% Child Support Rule in Canada

Reaching 40% parenting time changes the child-support analysis. It does not automatically make support zero and it does not turn section 9 into a simple subtraction formula.

The 40% threshold

Section 9 applies when each spouse exercises not less than 40% of parenting time with a child over the course of a year.

What the court must consider

Once section 9 applies, the amount of support must be determined by taking into account three statutory factors: the relevant table amounts for each spouse; the increased costs of shared parenting time arrangements; and the conditions, means, needs and other circumstances of each spouse and of the child.

Why people talk about an offset

Subtracting the lower table amount from the higher one can be a useful arithmetic comparison. But section 9 does not say that the difference is automatically the final support amount. That is why LegalCostCanada’s calculator labels its result as an arithmetic comparison rather than a legal determination.

Shared parenting can create additional costs

A child may need functioning homes in both households. Housing, transportation, clothing and other duplicated or increased costs can matter as part of the statutory analysis.

Parenting time and support are separate questions

The 40% threshold determines whether section 9 applies. It does not replace the broader child-support analysis or turn parenting arrangements into a support-only calculation.