Child Support Calculator (Ontario)

This calculator gives a general, educational estimate using the same basic logic as the Federal and Ontario Child Support Guidelines. It is not a substitute for a lawyer's calculation or a court order, and it cannot account for every factor in your specific situation. See How Child Support Is Calculated for the fuller picture.

Most people use each parent's line on their most recent Notice of Assessment or pay stubs as a starting point. If income varies, is self-employment income, or needs to be imputed for some reason, a lawyer or accountant can help identify the right figure to use.

This tool is designed for straightforward, primarily-one-household arrangements. If parenting time is closer to shared (each parent has the child close to half the time), the calculation generally works differently — see the Child Custody Time Calculator and Shared-Parenting Child Support guide.

No. This estimate is for general, educational purposes only. A court order or separation agreement should be based on verified income documents and, generally, legal advice — not on a self-serve online tool.

Child support outcomes depend on documented income, exact parenting-time arrangements, special expenses, and other case-specific facts a simple calculator cannot fully capture. A lawyer reviewing your actual documents may reach a different figure.

No. Costs like childcare, medical or dental expenses beyond insurance, or extracurricular activities (often called "Section 7 expenses") are generally handled separately from the base guideline amount. See Special and Extraordinary Expenses.

This calculator can only work with the figures you enter. If you suspect income is being hidden or understated, that is a situation to raise with a family lawyer, since it can affect both the support amount and disclosure obligations.

Not always. Support can continue for a child enrolled in full-time studies or unable to withdraw from parental charge for other reasons. See Does Child Support End When a Child Turns 18?

This tool follows the same general approach as the Guidelines tables, but it is a simplified, unofficial estimate — not a replacement for the government tables or a lawyer's calculation using your verified income.

Treat the number as a conversation starter. If you and the other parent are on similar pages, you may be able to reflect it in a written agreement; if not, or if your situation is more complex, speak with a family lawyer before relying on it.