Child Support Calculator Canada

How is child support calculated in Canada?

Child support in Canada is calculated using the Federal Child Support Guidelines, a set of rules and tables established under the Divorce Act and adopted by every province and territory except Quebec (which has its own model). The Guidelines use a table-based system where the monthly support amount is determined by three variables: the paying parent's gross annual income, the number of children, and the province or territory where the paying parent lives.

The Federal Child Support Tables were updated on October 1, 2025, reflecting changes in federal and provincial tax rates. Parents with incomes at or below $16,000 now have a basic table amount of $0, recognizing the higher cost of basic necessities at lower income levels. For incomes between $16,000 and $150,000, the tables specify exact monthly amounts in $1,000 increments. For incomes above $150,000, the tables provide a base amount at $150,000 plus a percentage of income over that threshold.

Each province and territory has its own table because provincial tax rates affect the formula. A parent earning $100,000 in Ontario will pay a slightly different amount than a parent earning $100,000 in Alberta or British Columbia. The differences are typically within 5% of each other, but they exist because the underlying formula accounts for the tax burden in each jurisdiction.

The table amounts represent the base child support obligation. Additional amounts may be owed for special or extraordinary expenses (Section 7 expenses), and the calculation changes for shared custody arrangements where each parent has the child at least 40% of the time.

Federal Child Support Table amounts by income

The table below shows approximate monthly child support amounts for selected income levels in Ontario for 1, 2, and 3 children. Amounts vary slightly by province. Use the calculator above for a province-specific estimate.

Shared custody: the 40% rule and set-off approach

When each parent has the child at least 40% of the time, the calculation changes under Section 9 of the Federal Child Support Guidelines. This is called shared custody or shared parenting time. The 40% threshold is measured over the course of a year, and it includes all time the child is in a parent's care, including overnight stays, weekends, holidays, and summer access.

In shared custody, the court uses a set-off approach as a starting point. Each parent's table amount is calculated based on their income. The parent with the higher table amount pays the difference between the two amounts to the other parent. For example, if Parent A's table amount is $1,200 per month and Parent B's table amount is $700 per month, Parent A pays $500 per month in child support.

The set-off is not automatic. Section 9 requires the court to consider three factors: the table amounts for each parent, the increased costs of shared parenting time arrangements, and the conditions, means, needs, and other circumstances of each parent and child. Courts have discretion to adjust the set-off amount when it does not reflect the actual cost distribution between households.

Shared custody at exactly 40% does not reduce child support to zero. The 40% threshold triggers a different calculation method, not an elimination of support. The Federal Court of Appeal has confirmed that the set-off approach is a useful starting point, but the final amount depends on the specific circumstances of each family.

Section 7: special and extraordinary expenses

In addition to the base table amount, parents may share special or extraordinary expenses under Section 7 of the Federal Child Support Guidelines. These expenses are added on top of the monthly table amount and are shared between the parents in proportion to their incomes.

Section 7 expenses include: childcare costs arising from employment, illness, disability, education, or training; the portion of medical and dental insurance premiums attributable to the child; healthcare expenses exceeding $100 per year that are not covered by insurance (orthodontics, therapy, prescription drugs, glasses); extraordinary expenses for primary or secondary school education; expenses for post-secondary education; and extraordinary expenses for extracurricular activities.

For an expense to qualify as a Section 7 expense, it must be necessary because it is in the child's best interests, reasonable in relation to the means of the parents and of the child, and consistent with the family's spending patterns prior to separation. The net cost of each expense (after any tax credits, subsidies, or deductions) is shared proportionally. For example, if one parent earns $80,000 and the other earns $40,000, the first parent pays two-thirds of each qualifying Section 7 expense.

Section 7 expenses are not included in the base table amount produced by this calculator. If you expect significant childcare, medical, or extracurricular costs, add those to the table amount to estimate your total child support obligation.

Undue hardship claims (Section 10)

Section 10 of the Federal Child Support Guidelines allows a parent to argue that the table amount would cause undue hardship to them or to the child. If the court agrees, it can order a different amount. The threshold for undue hardship is high, and successful claims are uncommon.

The Guidelines list specific circumstances that may constitute undue hardship: unusually high debts reasonably incurred to support the family before separation or to earn a living; unusually high expenses related to exercising access to the child (such as travel costs for long-distance parenting); a legal duty to support another person (a new spouse, a stepchild, or a child from another relationship); and a legal duty to support another child.

Even if a parent demonstrates a qualifying circumstance, the court applies a second test: a comparison of household standards of living. If the household of the parent claiming hardship has a higher standard of living than the other parent's household, the claim will be denied. This comparison uses Schedule II of the Guidelines, which accounts for household size, income from all sources, and the number of dependents.

Undue hardship is not intended to reduce child support simply because the payor has a high cost of living or lifestyle expenses. The word 'undue' means the hardship must be exceptional, excessive, or disproportionate in all circumstances. Courts treat the table amounts as a floor, not a ceiling, and rarely deviate downward.

How income is determined for child support

The starting point for income determination is line 15000 of the paying parent's most recent tax return (total income before deductions). However, the court may adjust this figure under Schedule III of the Guidelines. Common adjustments include adding back capital gains deductions, adding non-taxable income sources (such as workers' compensation or social assistance), and deducting union dues or self-employment expenses.

For self-employed parents, determining income requires more analysis. Courts look at the parent's actual income, not just what they report to the CRA. Business expenses that benefit the parent personally (a vehicle used partly for personal use, meals and entertainment) may be added back. Income averaging over multiple years is common for self-employed parents with fluctuating earnings.

The court can also impute income to a parent who is intentionally underemployed or unemployed. If a parent voluntarily quits a high-paying job, takes a lower-paying position without good reason, or fails to pursue reasonable employment opportunities, the court may base child support on what that parent could reasonably earn rather than what they actually earn. This is called imputed income.

Income over $150,000 triggers a different calculation. Section 4 of the Guidelines gives courts two options: apply the table formula to the full income (base amount at $150,000 plus a percentage of income above that), or award the table amount for the first $150,000 and exercise discretion for the remainder. In practice, most courts apply the table formula unless the resulting amount would be clearly excessive.

Worked examples: sole custody vs. shared custody

Scenario 1: Sole custody. Sarah has sole custody of two children. Michael, who lives in Ontario, earns $90,000 gross per year. Using the Federal Child Support Tables for Ontario with 2 children and an income of $90,000, the monthly table amount is approximately $1,602. Michael pays Sarah $1,602 per month ($19,224 per year) as base child support. If the children also have $800/month in daycare costs, those Section 7 expenses are shared proportionally based on both parents' incomes.

Scenario 2: Shared custody. James earns $120,000 and lives in British Columbia. Emma earns $65,000. They share custody of one child equally (50/50). James's table amount for 1 child is approximately $1,291 per month. Emma's table amount for 1 child is approximately $651 per month. Using the set-off approach, James pays Emma $640 per month ($1,291 - $651). The court may adjust this amount based on the actual cost distribution between the two households.

Scenario 3: High income. David lives in Alberta and earns $250,000 gross per year. He has 3 children. The table amount at $150,000 for 3 children in Alberta is approximately $3,198. For the $100,000 above $150,000, the additional amount is approximately $100,000 x 2.94% = $2,940 per month. Total estimated monthly child support: $6,138. At this income level, the court may exercise discretion under Section 4 rather than applying the formula mechanically.

Quebec: a different calculation model

Quebec does not use the Federal Child Support Guidelines. Instead, Quebec has its own child support determination model under the Regulation respecting the determination of child support payments. The Quebec model considers both parents' incomes (not just the paying parent's), the number of children, custody time percentages, and certain child-related expenses.

This calculator uses the Federal Child Support Guidelines tables and does not cover Quebec. If you live in Quebec or the paying parent lives in Quebec, use the official Quebec child support calculation tool available on the Gouvernement du Quebec website.

For interprovincial situations (one parent in Quebec, one in another province), the applicable model depends on which court has jurisdiction. Generally, the law of the province where the court proceeding takes place applies.