How to calculate the family size?
The family size is calculated on the day on which the application is filed and the sponsor must advise IRCC (via the
web form) of any change in the family composition. The size of the family determines the amount of income you need to sponsor.
Follow these steps to calculate the size of your family:
Step 1. How many family members are currently in your family unit?
Count the members of your family unit and include:
Step 2. How many people do you want to sponsor?
Count the number of parents and grandparents you want to sponsor AND their dependents (spouse or common-law partner and dependent children).
You must also include the dependents who will not come to Canada with your parents or grandparents.
Add the total number of persons covered in steps 1 and 2. This total number represents the size of your family unit. Look at the Minimum Necessary Income Table for Parents and Grandparents Sponsorship in this guide to help you decide if you have the financial ability to meet sponsorship requirements. Note that your calculations will only be an estimate.
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/application-forms-guides/guide-5772-application-sponsor-parents-grandparents.html