Free Tool — Ontario

Ontario Child Support Calculator

Estimate monthly child support based on the Federal Child Support Guidelines. Enter the payor's gross annual income and number of children to see the table amount.

Basic Child Support Calculator

Use the Federal Child Support Guidelines table for Ontario to estimate monthly payments.

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Monthly Child Support Amount
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Based on the Federal Child Support Guidelines table for Ontario
Important Disclaimer: This calculator provides estimates based on the Federal Child Support Guidelines tables for Ontario and is intended for informational purposes only. Actual child support may differ based on shared parenting arrangements, special expenses (Section 7), undue hardship claims, or other factors. This tool does not constitute legal advice. For an accurate determination of your child support obligations, book a consultation with one of our lawyers.

Section 7 — Special & Extraordinary Expenses

In addition to basic child support, courts can order parents to share special expenses in proportion to their incomes.

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Include childcare, medical/dental, educational, extracurricular activities, and post-secondary costs

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How Child Support Is Calculated

Child support in Ontario is determined by the Federal Child Support Guidelines. The amount is based primarily on two factors: the gross annual income of the paying parent and the number of children. The Guidelines use standardized tables — one for each province — to set a base monthly amount that reflects what a parent at that income level would typically contribute toward their child's expenses if the family were still together. These amounts are not negotiable — they are the legal starting point.

What Counts as Income?

Income for child support purposes is based on Line 15000 of the payor's income tax return (total income before deductions). However, courts can look beyond the tax return. If a parent is self-employed, earns cash income, has the use of a company vehicle, receives dividends rather than salary, or is intentionally underemployed, the court may impute income — that is, assign a higher income than what is reported. Full financial disclosure is mandatory under the Family Law Rules.

Shared and Split Custody

If each parent has the child at least 40% of the time (shared custody), the calculation changes. The court compares what each parent would pay under the tables and typically uses the difference — known as the "set-off" amount. Split custody (where each parent has primary care of at least one child) uses a similar offset approach. These arrangements require careful analysis.

When Can Child Support Be Changed?

Child support can be varied when there is a material change in circumstances — a significant change in income, a change in the parenting schedule, or a child reaching an age where support may no longer be required. Support does not automatically end at 18 in Ontario — it continues as long as the child remains a dependent, which often means through post-secondary education. Retroactive support claims can also be brought if a parent was underpaying.

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Frequently Asked Questions

Click to expand each question for answers about Ontario child support.

Does child support end when my child turns 18?
Not necessarily. In Ontario, child support continues as long as the child is a dependent. If the child is enrolled in full-time education, support typically continues through post-secondary. The obligation ends when the child becomes financially independent.
Can child support be changed if I lose my job?
Yes. A significant change in income is a material change in circumstances. You can bring a motion to vary the support order. However, you must act promptly — the court will not retroactively reduce support for periods before you sought the variation. Until a court changes the order, the existing amount remains in effect.
Do I still pay child support if my ex remarries?
Yes. Child support is the right of the child, not the other parent. The income of a new spouse or partner does not reduce the payor's obligation. However, a new partner's income could be relevant when calculating Section 7 expense sharing in some circumstances.
What if the other parent won't disclose their income?
You can bring a motion to compel financial disclosure. If the other parent refuses to disclose, the court can impute income based on available evidence — including lifestyle, spending, and prior tax returns. Courts take non-disclosure very seriously.
What are Section 7 expenses?
Section 7 expenses are special or extraordinary costs that go beyond basic child support. They include childcare, medical and dental insurance premiums, health-related expenses exceeding $100 per year, educational expenses, post-secondary costs, and extracurricular activities. These are shared between parents proportionally based on income.
Is child support tax deductible?
No. Under current Canadian tax law, child support payments are neither deductible by the payor nor taxable income for the recipient. This changed in 1997 — agreements made before May 1997 may follow different rules.

Need help with child support?

Whether you are seeking support, responding to a claim, or need to vary an existing order — we can help. Book a consultation to discuss your specific situation.

Book a Consultation (416) 826-1155