How Is Child Support Calculated in Canada?

The Federal Child Support Guidelines

In Canada, child support is determined by the Federal Child Support Guidelines, enacted under the Divorce Act. These guidelines are used in most provinces and territories. Quebec has its own model (covered below), and a few other provinces have adopted their own guidelines that largely mirror the federal ones.

The guidelines use a table-based system. The base amount of child support depends on two factors:

1. The paying parent's annual income (gross, before taxes)
2. The number of children requiring support

The tables are published by the Department of Justice and are organized by province or territory of residence. The paying parent looks up their income in the table for their province, and the corresponding amount is the base monthly child support obligation.

Why the province matters

The federal tables exist for each province because provincial tax rates differ. Since child support amounts are designed to reflect what the paying parent can afford after taxes, the table amounts vary by province even at the same income level. An income of $80,000 in Alberta produces a different table amount than $80,000 in Nova Scotia.

Shared Custody (Section 9)

When each parent has the child at least 40% of the time, the standard table amount does not apply directly. Instead, section 9 of the Guidelines uses a set-off approach:

1. Look up each parent's table amount (as if each were the sole payor)
2. Subtract the lower amount from the higher
3. The parent with the higher table amount pays the difference

This reflects that both parents bear direct costs of caring for the child during their parenting time. The 40% threshold is measured by overnight stays or equivalent time.

Split Custody (Section 8)

Split custody applies when each parent has primary care of at least one child. For example, the older child lives primarily with one parent and the younger child with the other.

In this case, each parent's table amount is calculated for the children in the other parent's care, and the amounts are set off against each other.

Section 7: Special and Extraordinary Expenses

Beyond the base table amount, section 7 of the Guidelines covers additional expenses that are shared between both parents in proportion to their incomes. These include:

• Child care (daycare, after-school care)
• Health-related expenses (dental, orthodontic, therapy, prescription drugs not covered by insurance)
• Education expenses (tutoring, private school fees, post-secondary costs)
• Extracurricular activities (sports, music lessons, camps)

Both parents contribute to these expenses based on their share of combined income. If one parent earns 60% of the combined household income, they pay 60% of the section 7 expenses.

High Income ($150,000+)

The federal tables cover income up to $150,000 in detail. Above that threshold, the Guidelines provide a base amount for $150,000 plus a percentage for each dollar above. Courts also have discretion to set a different amount if the table amount is inappropriate given the circumstances.

Quebec: A Different Model

Quebec does not use the Federal Child Support Guidelines. Instead, it uses the Basic Parental Contribution (BPC) model under the Regulation respecting the determination of child support payments.

The key differences:

• Both parents' incomes matter from the start. The BPC table uses the combined disposable income of both parents, not just the paying parent's income.
• Each parent's share is proportional. The BPC is divided between parents in proportion to their share of the combined income.
• Different expense categories. Quebec's model accounts for three categories of additional expenses (child care, post-secondary education, and special needs), with different allocation rules.
• Income ceiling. The BPC table covers combined disposable income up to $200,000, with extrapolation above that.

If you live in Quebec, the calculation process is different enough that the province-specific details matter. Our calculator handles both the federal model and the Quebec BPC model automatically based on your province of residence.

What Affects the Final Amount

Several factors can adjust the base table amount:

• Parenting time arrangement (sole, shared at 40%+, or split)
• Section 7 special expenses (shared proportionally)
• Undue hardship claims (unusual circumstances like high debt or travel costs for access)
• Income above $150,000 (discretionary component)
• Imputed income (if a parent is voluntarily underemployed, the court may use a higher income)

The Guidelines are designed to produce consistent, predictable outcomes. Most child support determinations follow the tables directly, with adjustments only where the specific circumstances warrant it.