The Federal Child Support Guidelines: Step-by-Step

Step 2: Determine the number of children requiring support

This step will help you determine the number of children you will be supporting. This is important because the Federal Guidelines take into account the number of children to establish child support amounts.

Even if you separate or divorce, you are still parents. And, as parents, it is important that you keep supporting your children, just as you did when the family was still together.

Age of majority means the age when a child legally becomes an adult in the province or territory where the child lives. Depending on your province or territory, this is 18 or 19. If the child lives outside Canada, the age of majority is presumed to be 18.

The age or the situation of a child may affect the way you calculate child support.

The Divorce Act says that you have to support any “child of the marriage.” These are children you had together during your marriage, including adopted children, who:

Louis and Jocelyn

Louis and Jocelyn have four children:

  • Sam is 16
  • Tom is 14
  • The twins, Theo and Camille, are 20

Louis and Jocelyn are divorcing. They have established that the Federal Guidelines apply to their situation. They now need to determine which of their children are “children of the marriage”—that is, which ones are dependent and need their financial support.

Tom and Sam are both under the age of majority and are still dependent. Louis and Jocelyn have an obligation to support them.

Theo is married and working full-time. He is independent and is not entitled to support.

Camille is pursuing post-secondary education full-time in another province. She lives on campus, and both Louis and Jocelyn have been paying her tuition and living expenses. Louis and Jocelyn agree that she still depends on them and that they will continue to support her financially after the divorce until she graduates.

Acting in place of a parent

If either of you has been acting as a parent to the child of your spouse or partner—for example, some step-parents are in this situation—you or a court may decide that you should pay support for that child. Either you or the court would consider the duty of any other person to support the child before deciding on an appropriate child support amount.


Kay has always been very close to her stepson, Emile. She helped raise him since marrying Emile’s father, Norman, nine years ago. Emile was then two years old. He is now 11.

Her marriage to Norman has fallen apart and they decide to divorce. But Kay is still very attached to Emile. She does not want him to suffer financially from her break-up with Norman. She and Norman agree that she did act in place of a parent to Emile and that she will pay child support for him. Emile’s birth mother, Sarah, is also paying child support for Emile each month. Kay and Norman know that they should take this into account in working out the appropriate amount of child support. They decide to ask a legal adviser to help them.

Child at or over the age of majority

The age of majority is 18 years in Alberta, Manitoba, Ontario, Prince Edward Island, Quebec, and Saskatchewan.

The age of majority is 19 years in British Columbia, New Brunswick, Newfoundland and Labrador, the Northwest Territories, Nova Scotia, Nunavut, and the Yukon.

The Federal Guidelines set out specific rules for calculating support for a child under the age of majority. For a child at or over the age of majority, you can use the same rules. Or, if you find that this approach is not appropriate, you may agree to base the amount of support for an older child on:

George and Anne

George and Anne are getting a divorce. They decide to use the family justice services offered by their provincial government and try mediation to come up with an agreement about the support of their 20-year-old daughter, Claire.

During their mediation sessions, they determine that Claire still depends on them and that they should continue to support her while she pursues post-secondary education. They decide that the rules for a child under the age of majority are not appropriate in their situation. Instead, they look at Claire’s needs, means and other circumstances, as well as their own financial ability to contribute. They agree that some of Claire’s financial needs can be covered by the Registered Education Savings Plan they set up for her and by student loans she receives, as well as by some of the money she earns working part-time.

With the help of the mediator, they then set up an appropriate child support agreement based on the ability of each of them to contribute financially to support Claire.


Remember, your obligation to support your children financially does not automatically end because they have reached the age of majority.

You have determined:

You may want to put the number of children requiring support into section 3 or section 10 of your Child Support Tool, as applicable.