Child Support in Ontario: How It's Calculated

How Much Is Child Support in Ontario?#

Child support in Ontario is not discretionary. It is set by the Federal Child Support Guidelines, which contain province-specific tables that assign a monthly amount based on two factors: the paying parent’s gross annual income and the number of children.

For example, a parent in Ontario earning $80,000 per year with one child pays approximately $743 per month in base child support. That same parent with two children would pay roughly $1,220 per month. These are base table amounts only. The actual obligation may be higher once section 7 expenses (daycare, medical, extracurricular activities) are added on top of those base amounts.

Child support is the right of the child, not the receiving parent. It is mandatory, and parents cannot permanently waive or contract out of it. Even where parents agree to a different amount, the court retains overriding jurisdiction to set support in accordance with the Guidelines if a parent later changes their mind. In my practice, courts rarely depart from the amount stated in the table.

The Federal Child Support Guidelines Table: What You’ll Pay#

The table below shows approximate monthly child support amounts under the current Federal Child Support Guidelines for Ontario (effective October 1, 2025). These figures are base amounts only and do not include section 7 expenses.

Note: Under the 2025 tables, if a parent earns $16,000 per year or less, the table amount is zero. For incomes above $150,000, the court applies the table amount, unless the court finds that the table amount is inappropriate given the circumstances (Francis v. Baker, [1999] 3 SCR 250).

These amounts are drawn from the Federal Child Support Guidelines tables and reflect round income levels. The tables list amounts in rounded increments, so your exact obligation may differ. Use the Department of Justice lookup tool for the precise figure based on your province and income.

How Child Support Is Calculated: The Basic Formula#

The calculation starts with three pieces of information:

1. The payor’s gross annual income. This is typically Line 15000 of the T1 General tax return, though adjustments are common.
2. The number of children. Each additional child increases the monthly obligation.
3. The province where the payor resides. Each province has its own table. If the payor lives outside Canada, the table for the province where the recipient parent lives applies.

Once you have these three inputs, the table produces a single monthly figure. The table amount is presumptive. Courts should order it unless a specific exception applies, and parents should not simply pick a different number.

Line 15000 Is the Starting Point, Not the Ending Point#

While Line 15000 (total income before deductions) is the usual reference, the Guidelines allow adjustments. Courts may add back non-recurring losses, employment-related benefits (company car, housing allowance), or adjust for self-employment deductions and capital gains. For a parent who is self-employed or controls a corporation, Line 15000 is often an incomplete picture: the analysis typically extends to the corporation’s pre-tax income under section 18 of the Guidelines. The goal is to determine what the parent actually has available to support the children.

Section 7 Expenses: The Costs Beyond Table Support#

Table amounts cover basic needs like food, clothing, shelter, and standard school supplies. Section 7 of the Guidelines addresses additional expenses that fall outside those basics. These are shared between parents in proportion to their respective incomes.

Section 7 expenses include:

• Childcare costs required so that the recipient parent can work, attend school, or pursue training
• Medical and dental insurance premiums attributable to the child
• Health-related expenses exceeding $100 per year above insurance coverage (orthodontics, therapy, prescription medications)
• Extraordinary expenses for extracurricular activities (competitive sports, music lessons, travel teams)
• Post-secondary education expenses
• Expenses for primary or secondary school education to meet a child’s particular needs (private school tuition, tutoring)

How the Proportional Sharing Works#

If one parent earns $100,000 and the other earns $50,000, their combined income is $150,000. The higher-earning parent covers 66.6% (two thirds) of section 7 expenses, and the lower-earning parent covers 33.3% (one third). In practice, section 7 expenses are typically shared net of any related tax benefits, subsidies, or credits (for example, the childcare expense deduction), so the amount actually split between the parents is the cost after those savings are taken into account.

Example: Daycare costs $1,200 per month. The parent earning $100,000 pays $800 per month toward daycare. The parent earning $50,000 pays $400 per month. This is on top of the table amount.

Whether an extracurricular activity qualifies as a section 7 expense depends on a number of factors, and can include the child’s involvement before separation, the overall cost, and the family’s means. A child who played competitive hockey before the parents separated will likely have that expense treated as extraordinary. A new activity that costs $50 per month likely falls within the table amount.

Shared Parenting: The 40% Rule#

When a child spends at least 40% of their time with each parent, section 9 of the Guidelines applies. This is commonly referred to as “shared parenting time”.

Under section 9, the court considers:

1. The table amounts that each parent would pay the other
2. The increased costs of shared custody / parenting time (maintaining two homes equipped for the child)
3. The conditions, means, needs, and circumstances of each parent and the child

The starting point is a set-off approach: each parent’s table amount is calculated, and the difference is the base obligation. But the court is not required to simply order the set-off. In Contino v. Leonelli-Contino, 2005 SCC 63, the Supreme Court of Canada held that all three factors under section 9 must be considered, and the set-off is only the beginning of the analysis.

Example: Parent A earns $100,000 and Parent B earns $60,000. The children spend equal time with each parent. Parent A’s table amount for two children is $1,517. Parent B’s table amount for two children is $911. The set-off is $606 per month payable by Parent A. But the court may adjust this amount up or down after considering the other section 9 factors.

Split Custody / Parenting Time#

Split custody arises when each parent has primary care of at least one child. Under section 8 of the Guidelines, each parent pays the other the table amount for the children in the other parent’s care. The amounts are then set off, and the parent owing more pays the difference.

When Income Is Imputed#

Sometimes a parent’s reported income does not reflect what they are actually capable of earning. In those situations, the court can impute income under section 19 of the Guidelines.

Courts may impute income when a parent:

• Is intentionally underemployed or unemployed
• Fails to provide income information
• Lives in a country with lower tax rates
• Diverts income to reduce child support
• Receives income from a trust
• Earns unreasonably low income through a corporation they control
• Fails to make reasonable efforts to find employment

In Drygala v. Pauli, 2002 CanLII 41868 (ONCA), the Ontario Court of Appeal confirmed that when imputing income for intentional underemployment, the court should consider what the parent could reasonably earn given their age, education, experience, skills, health, and the available job market.

A parent cannot quit their job to reduce child support. If they do, the court may calculate support based on what they should be earning, not what they choose to earn.

Self-Employment and Corporate Income#

For self-employed parents or those who control a corporation, the salary or dividends the parent chooses to draw rarely tells the full story. Under section 18 of the Guidelines, where a parent is a shareholder, director, or officer of a corporation and the court is not satisfied that the parent’s section 16 income fairly reflects the money available for support, the court can include all or part of the corporation’s pre-tax income in the parent’s Guidelines income. Retained earnings, personal expenses paid through the business, and discretionary write-offs are common signals that the personal tax return understates what is actually available — and they often drive the court to look through to the corporation’s pre-tax income rather than stopping at Line 15000.

Child Support for Adult Children#

Child support does not automatically end when a child turns 18. Under section 3(2)(b) of the Guidelines, a child who is over the age of majority but unable to withdraw from parental charge remains entitled to support. The most common reason is enrollment in full-time post-secondary education.

For adult children, if the court finds the standard table amount inappropriate, it may order a different amount it considers suitable, or a combination of table support plus a contribution to specific educational expenses. The child’s own resources, including employment income, scholarships, and student loans, are factored into the analysis.

Undue Hardship#

Section 10 of the Guidelines allows a parent to claim that paying (or receiving) the table amount would cause undue hardship. This is a high threshold. The court will only consider an undue hardship claim if the parent’s household standard of living is lower than the other parent’s household standard of living, measured on a per capita basis.

Circumstances that may constitute undue hardship include unusually high debts from the marriage, unusually high access costs (long-distance travel), or a legal obligation to support another dependent (a child from another relationship, or a disabled dependent). I have seen very few of these claims succeed in practice, likely because courts are reluctant to reduce child support below the table amount given that the tables already account for the payor’s tax obligations and basic living costs.

Changing Child Support#

Child support is not a one-time calculation. Either parent can apply to vary the amount when there is a material change in circumstances, such as a significant change in income, a change in parenting time, a child finishing school, or a change in section 7 expenses.

In D.B.S. v. S.R.G., 2006 SCC 37, the Supreme Court of Canada held that courts can order retroactive adjustments when a payor’s income has increased and they failed to disclose the increase. Parents should exchange financial information annually. Under the Guidelines, the payor must provide updated income information every year upon request.

Enforcement Through the Family Responsibility Office#

In Ontario, child support orders are automatically filed with the Family Responsibility Office (FRO). FRO enforces support by garnishing wages, intercepting federal payments (tax refunds, EI benefits), suspending driver’s licences and passports, reporting defaults to credit bureaus, and initiating contempt proceedings that can, in the most extreme cases, result in imprisonment.

If a parent falls behind, FRO pursues arrears aggressively. Interest accrues on unpaid amounts, and courts are reluctant to reduce arrears that have already accumulated.

A Full Calculation: Sarah and Michael#

Sarah and Michael have two children, ages 8 and 11. They separate, and the children live primarily with Sarah. Michael earns $90,000 per year as a project manager. Sarah earns $45,000 per year as an office administrator.

Step 1: Table Amount Michael’s table amount for two children in Ontario at $90,000 is approximately $1,372 per month.

Step 2: Section 7 Expenses The children’s expenses include:

• After-school care: $800/month
• Competitive soccer for the older child: $300/month
• Orthodontics: $200/month

Total section 7 expenses: $1,300 per month.

Step 3: Proportional Sharing of Section 7 Expenses Combined income: $90,000 + $45,000 = $135,000. Michael’s share: 66.6% ($90,000 / $135,000). Sarah’s share: 33.3% ($45,000 / $135,000).

Michael pays 66.6% of $1,300 = $866 per month toward section 7 expenses. Sarah pays 33.4% of $1,300 = $434 per month toward section 7 expenses.

Step 4: Michael’s Total Monthly Obligation Table amount: $1,372 + Section 7 share: $866 = $2,238 per month.

This example shows why the total child support obligation is often substantially more than the table amount alone, especially when section 7 expenses are significant.

What the Law Says#

Child support in Ontario is governed by two statutes, depending on whether the parents were married:

• The Divorce Act (federal): Applies to married parents who are divorcing. Incorporates the Federal Child Support Guidelines.
• The Family Law Act (Ontario): Applies to unmarried parents and to married parents seeking support outside of a divorce proceeding. Ontario adopted the federal Guidelines tables through Ontario Regulation 391/97.

Both statutes produce the same table amounts. The child support obligation is the same whether parents were married, common-law, or never lived together.

Child support and spousal support are separate obligations. A parent may owe both. Child support is calculated first, and the child support amount is then factored into the spousal support calculation.

Frequently Asked Questions#

Get Advice on Your Child Support Situation#

Child support becomes more complicated when income is irregular or self-employed, parenting time is shared, or section 7 expenses are disputed. If you need help understanding your obligations or enforcing a support order, contact Krol & Krol to discuss your situation.