What is the basic level of child support that he may have to pay as a non-custodial parent?

This is the case,

He and his wife were childhood sweethearts.He says they are the best of friends but not so much lovers anymore.They have been married 20 years.His wife has a degree and worked before coming to Canada, but has not worked since coming to Canada and she has limited English skills.She has been dependent financially for the last 4 years and is the, primary caregiver to their children (one of which was born in Canada).They agreed to this before moving to Canada.She has sacrificed her career to support his endeavours and expanding their family in Canada.He states that he has no immediate plans to separate or divorce but is wondering about some general financial advice.After advising him that you are not giving legal adviceand recommend that he seek this out (and recording that you have done so!). . .