Canadian family law · Support arrears
Support indexation calculator.
Apply the cost of living method your order uses to a support amount and see the new amount, year by year.
Inputs
Adjusted support
Enter the support amount and the adjustment.
How is indexation of support calculated in Canada?
Many support orders include a yearly cost of living adjustment. In Ontario, the regulation that sets the ways such adjustments can be calculated for orders enforced by the Family Responsibility Office (O. Reg. 176/98) lists: a calculation using cost of living adjustment factors derived from any part of the Consumer Price Index; the greater or the lesser of the percentage change in the payor's or recipient's income and the percentage change in the CPI, as the order specifies; a rate of increase or decrease specified in the order; the methods in Quebec legislation; and the indexing factor an income source applies to the payor's income. Your order says which applies.
This tool applies the first three. Enter the CPI percentage from Statistics Canada, or the rate from your order. It does not look up CPI for you. Each year's new amount is the previous amount times (1 + rate), rounded to the cent, and the same rate is repeated for each adjustment you ask for.
Worked example. $1,000 a month with a 2.5% CPI change for 3 years gives $1,025.00, $1,050.63, $1,076.90. With the lesser of a 2% CPI change and a 4% income change, $1,000 becomes $1,020.00.
Frequently asked questions
How do you calculate a cost of living adjustment on support?
Multiply the current amount by one plus the percentage change that your order specifies, expressed as a decimal. A 2.5% change on $1,000 gives $1,025.00.
What methods can an Ontario order use?
O. Reg. 176/98 lists CPI factors, the greater or lesser of the income change and the CPI change as specified in the order, a rate specified in the order, Quebec legislation methods and an income source's indexing factor.
Where do I find the CPI figure?
Statistics Canada publishes the Consumer Price Index. Use the period and series your order refers to.
Are federal table child support amounts indexed automatically?
The Schedule I tables were replaced by regulation on 1 October 2025, and Justice Canada says the update does not automatically apply to orders made before that date. Whether your own order is indexed is a term of that order or agreement.
Does indexation apply to arrears?
That depends on the wording of your order or agreement. Use the arrears calculator for unpaid amounts and ask FRO or a lawyer how adjustments and interest apply.
Sources
Checked
- Ontario Regulation 176/98: Cost of Living Adjustments, Methods of Calculation
- Statistics Canada: Consumer Price Index
- Justice Canada: FAQ on the 2025 update to the Federal Child Support Tables
The method list is O. Reg. 176/98 s.1. CPI percentages are not supplied here; you enter them. The statement that tables are not automatically applied to older orders is from the Justice Canada FAQ. Runs entirely in your browser. Nothing you type is sent or stored.
Not legal advice
Information only, not legal advice. A court or a signed agreement decides the actual amount, and either can differ from a formula. Speak to a family lawyer, a family law information centre or your provincial family justice service about your own situation.