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Spousal Support Formulas in Ontario: With and Without Child Support

Learn which Spousal Support Advisory Guidelines formula applies in Ontario, with or without child support, and why the amounts and durations differ.

Family Law4 min readTSLBy the Treadstone Law Team · OntarioUpdated November 13, 2026
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Key takeaways
  • The Spousal Support Advisory Guidelines are not law, but judges often base spousal support decisions on them.
  • The without child support formula looks at the income difference and the years of cohabitation, while the with child support formula aims to leave the lower-income recipient with 40% to 46% of the couple's combined Individual Net Disposable Income, which is income after child support, taxes and deductions.
  • A zero result under the with child support formula is not the same as no entitlement.

If you are separating in Ontario, you may hear that spousal support is "just a formula." In practice there are two main formulas, and which one applies depends mainly on whether child support is also being paid. The results can look very different.

This article explains what the formulas are, how they differ, and where they stop working. It is general information, not a calculation of what you would pay or receive.

The guidelines are a tool, not the law

The Spousal Support Advisory Guidelines (SSAG) are not law, but judges often base spousal support decisions on them. They were designed for the federal Divorce Act, and courts and lawyers also often use them under provincial legislation such as Ontario's Family Law Act.

The formulas only come into play once you have a right to support. They do not decide entitlement, which must first be established under the applicable law. An income gap on its own does not create entitlement. Entitlement can be compensatory (loss or disadvantage from roles in the relationship), non-compensatory (need), or contractual.

The without child support formula

This formula is used when there is no child support in the picture. For the amount, support ranges from 1.5% to 2% of the difference between the spouses' gross incomes for each year of cohabitation. The cap is 50%, and the top of the range cannot exceed the amount that would equalize the spouses' net incomes.

For duration, support lasts 0.5 to 1 year for each year of cohabitation. It is indefinite if the marriage lasted 20 years or more, or under the "rule of 65": the marriage lasted at least five years and the years of marriage plus the recipient's age at separation total 65 or more.

"Indefinite" does not necessarily mean permanent. It only means no time limit can be set when the order or agreement is made, and the support stays subject to variation and review. Short marriages produce very limited awards, if there is entitlement at all, and the rule of 65 does not apply to marriages under 5 years.

The with child support formula

When child support is being paid, the approach changes. A court deciding both child support and spousal support must give child support priority. The formula range is the amount of spousal support that leaves the lower-income recipient with 40% to 46% of the couple's combined Individual Net Disposable Income (INDI). INDI is income after child support, taxes and deductions.

Initial orders are indefinite but have outer limits that apply on review or variation. The upper limit is the longer of the length of the marriage or the date the youngest child finishes high school. The lower limit is the longer of half the length of the marriage or the date the youngest child starts full-time school.

QuestionWithout child supportWith child support
How is the amount set?1.5% to 2% of the gross income difference per year of cohabitation40% to 46% of combined INDI to the recipient
How is duration set?0.5 to 1 year per year of cohabitation, or indefinite in some casesIndefinite, with outer limits on review or variation

A zero result is common under the with child support formula because child support comes first. That is not the same as no entitlement. It may simply reflect a current inability to pay.

When the formula does not fit

The formulas do not apply mechanically at the extremes. Above a payor income of $350,000, discretion is used, and incomes below $20,000/$30,000 require adjustments.

Online calculators can help you get oriented, but the free one Ontario links to considers only employment income and simple calculations.

What to do next

Frequently asked questions

Which formula applies to me?

Generally it depends on whether child support is also being paid. The without child support formula looks at gross income difference and years together, while the with child support formula looks at net disposable income after child support.

Are the guidelines binding on a judge?

No. They are not law, but judges often base their decisions on them. They also do not decide whether you are entitled to support in the first place.

Does a zero range mean I will never get support?

Not necessarily. A zero range under the with child support formula may just reflect a current inability to pay, since child support comes first.

Can my support be higher or lower than the formula suggests?

Yes, in recognized situations such as debt payments, illness or disability, or a child's special needs. Whether your facts qualify is worth confirming with a lawyer.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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