Calculator Tools
Parenting Time Schedule
Build your parenting schedule by clicking days on a calendar
Child Support Impact
Calculate child support based on your parenting time percentage
Printable Worksheet
Generate a professional worksheet with calendar and figures
Retroactive Support Calculation
A reliable retroactive calculation has to use the actual income for each past year and the correct Federal Guideline table that was in force that year (the current Federal Child Support Tables took effect on October 1, 2025; earlier periods use the 2017, 2011, or 2006 tables). Our dedicated Child Support Calculator has a year-by-year retroactive engine that does exactly that.
Retroactive claims are generally subject to the three-year presumptive limit from D.B.S. v. S.R.G., 2006 SCC 37, although a court can reach further back where there has been blameworthy conduct.
Open the Child Support Calculator (Retroactive)For an accurate retroactive figure for your own situation, please book a consultation.
How Parenting Time Works
The 40% Threshold
Under Section 9 of the Federal Child Support Guidelines, when each parent has the child at least 40% of the time, the set-off amount is usually the starting point. The court also considers increased costs and each household's means (section 9).
Set-Off Approach
Both parents' support obligations are calculated based on their income, and the difference is paid by the parent with the larger obligation. This creates a more balanced approach in shared custody situations.
Counting Methods
Courts may count overnights (for young children) or full days (24-hour blocks) when determining percentage time. The same method should be used consistently.
Contino Factors
Contino v. Leonelli-Contino, 2005 SCC 63, is the section 9 shared-parenting child support analysis. It is not the test for parenting decisions.
Frequently Asked Questions
Need Help with Parenting Time?
Our family lawyers at Persaud Hussain LLP can help you understand parenting time calculations and child support figures for an Ontario matter.
Persaud Hussain LLP is an Ontario family law firm. This calculator covers all provinces and territories for general information only. We advise on Ontario matters. It does not constitute legal advice.