Courtready has launched a free Ontario spousal support and child support calculator that estimates monthly amounts under the Spousal Support Advisory Guidelines and the Federal Child Support Guidelines, and shows the reasoning behind every figure. It covers the five parenting arrangements the with-child formulas treat differently, for couples who both live in Ontario.
Spousal support is one of the hardest numbers to pin down after a separation. Many online tools hand you a single figure with no way to see how it was reached, whether it fits your arrangement, or how long it is meant to last. For a self-represented spouse trying to understand what the law actually expects, a bare number is not much help.
The Ontario Spousal Support and Child Support Calculator estimates monthly spousal support under the Spousal Support Advisory Guidelines (SSAG), the with-child formulas, alongside child support under the Federal Child Support Guidelines (SOR/97-175). It is free, it requires no signup, and it is built for couples who both ordinarily reside in Ontario.
What the calculator does
Enter each spouse’s annual income, the dates of the relationship, and where each child lives, and the calculator returns three things: a monthly spousal support range, the child support that goes with it, and an estimate of how long spousal support is expected to last. The spousal figure is given as a low, a midpoint, and a high amount, because the Guidelines set ranges rather than a single number. The tool reads the parenting arrangement and applies the formula that matches it.
The five arrangements it handles
Where there are children, the Guidelines do not use one formula. They use several, depending on where the children live, and the calculator picks the one that fits:
- Basic. The children live mainly with the lower earner. That spouse receives child support and spousal support, and the spousal amount is worked out after the child support is set.
- Shared. The children divide their time roughly equally between the two homes. Child support is usually based on the difference between each parent’s table amount, and the spousal figure follows from there.
- Split. At least one child lives mainly with each spouse, so each parent supports the child or children living in the other’s home.
- Hybrid. A mix of the above, with at least one child shared between the homes and at least one child living mainly with one spouse. The calculator blends the two treatments.
- Custodial payor. The children live mainly with the higher earner, who pays spousal support to the lower earner while still receiving child support from them. The two run in opposite directions and are not set off against each other.
Every number comes with its reasoning
Alongside the amounts, the calculator produces a plain-language explanation of how it got there: which formula applies, how each spouse’s net disposable income was worked out, and where the low, midpoint, and high figures fall. Nothing is hidden behind a single output box.
The with-child formula does not work off gross income alone. It looks at what each spouse actually keeps each year after income tax, child support, and government child benefits. That amount is each spouse’s net disposable income. The formula then sets spousal support so the lower earner ends up with a target share of the two net disposable incomes combined, which is why the child support figure and the parenting arrangement both move the spousal result. The calculator uses Ontario tax brackets, credits, and child benefits to do this.
How long spousal support lasts
Where there are dependent children, an initial order is generally indefinite, which means no fixed end date is set at the start, subject to review and variation as circumstances change. The Guidelines still suggest a range of years, drawn from the length of the relationship and the ages of the children, and the calculator shows that range as a guide for review rather than a hard cap. The Guidelines are advisory, so the range is a sourced starting point for both amount and duration, not a binding result.
What it does not decide
The Guidelines, and this calculator, assume that entitlement to spousal support has already been established. They do not decide whether support is owed in the first place. Entitlement depends on factors like the roles each spouse took during the relationship, the financial effect of the separation, and whether the spouses have an agreement. If entitlement is in doubt, that is a question for a lawyer, and the figures here only apply once it is settled.
What it does not do yet
This first version is deliberately scoped. It applies to couples who both live in Ontario, and it uses Ontario tax and benefit figures. It does not calculate section 7 special or extraordinary child expenses, very high or very low incomes, restructuring of amount against duration, or self-sufficiency arguments, and it does not decide entitlement. Those are circumstances a court can weigh, and they are the honest reason to treat the result as a well-sourced starting point rather than a final answer.
If you only need child support, or you live outside Ontario, our Canadian Child Support Calculator covers every province and territory, and you can read how it works in our note on the child support calculator.
Who it is for
The tool is built for self-represented litigants who need to understand the with-child formulas, and for lawyers and mediators who want a fast, transparent starting figure they can check at a glance.
Family law sees some of the highest rates of self-representation in the country, and spousal support is often the number that is hardest to talk about and easiest to get wrong. A calculator that explains itself, rather than one that hands over a figure and asks you to trust it, gives a separating spouse something they can actually carry into a negotiation or a courtroom. That is the point of building it this way.
We built this to make spousal support easier to calculate.