Ontario Canadian Child Support Calculator

Ontario child support uses the Federal Child Support Guidelines (SOR/97-175) table amount system based on the paying parent's gross annual income and number of children. The 2025 Federal Tables, effective October 1, 2025, specify exact monthly amounts—for example, $556/month at $60,000 income or $710/month at $80,000 income for one child. Parents look up their income on Line 15000 of their tax return and find the corresponding table amount.

Section 7 of the Federal Child Support Guidelines covers special or extraordinary expenses paid in addition to the table amount. These include childcare costs, medical and dental insurance premiums, health expenses exceeding $100/year (orthodontics, glasses, therapy), extraordinary extracurricular activities, and post-secondary education costs. Parents share these expenses proportionally based on their incomes—if one parent earns $100,000 and the other $50,000, they split Section 7 costs two-thirds and one-third respectively.

When each parent has parenting time of at least 40% (approximately 146 days/year), Section 9 of the Federal Child Support Guidelines applies the set-off calculation. Each parent's table amount is determined based on their income, then the lower amount is subtracted from the higher. For example, if Parent A's table amount is $710/month and Parent B's is $439/month, Parent A pays the $271 difference to Parent B even with equal parenting time.

Ontario child support calculations start with the paying parent's gross annual income from Line 15000 (formerly Line 150) of their most recent tax return. This includes employment income, self-employment income, investment income, rental income, and pensions. For self-employed parents or those with corporate income, courts may adjust the Line 15000 figure to reflect actual available income.

Child support in Ontario can be varied when there's a material change in circumstances under Section 37 of the Family Law Act or Section 17 of the Divorce Act. Common triggers include significant income changes (job loss, promotion), changes in parenting time arrangements crossing the 40% threshold, or changes in the child's needs. The change must be substantial, ongoing, and not anticipated when the original order was made.

While Ontario's age of majority is 18, child support routinely continues beyond this age under Section 31(1) of the Family Law Act. Support extends for children enrolled in full-time post-secondary education, typically until completion of their first undergraduate degree. Courts apply the Farden Factors to assess whether an adult child remains entitled to support, considering their education plan, eligibility for student loans, and ability to contribute through part-time work.

For income exceeding $150,000, Section 4 of the Federal Child Support Guidelines gives courts discretion. Courts may either apply the full table amount for all income (the strong presumption established by the Supreme Court of Canada), or apply the table for the first $150,000 and add an appropriate amount for income above that threshold. Ontario courts have upheld table amounts even for incomes of $1.65 million, resulting in support awards of $11,000/month.

Extracurricular activities may qualify as Section 7 extraordinary expenses if they are necessary for the child's best interests and reasonable given the parents' means. The expense must exceed what the receiving parent can reasonably cover from the table amount. A $200 house-league fee typically won't qualify, but $8,000 in competitive hockey fees with travel and specialized coaching likely would. Both parents must consent to extraordinary expenses or obtain a court order before sharing costs.