age 18
see link below
They have to be 18.
16
He has to be 18.
You have to be 18.
!* 18
Canada has no specific law addressing this.
They have to be 18.
age 18 see links
Here the child at 16 years can not decide where she or he wants to live. As they are minors the court will decide it for them.
In Washington State, there is no specific age at which a child can decide which parent they want to live with. However, the court may take the child's preferences into consideration if they are deemed to be mature enough to express reasoned and intelligent opinions about their custodial arrangement. Generally, older teenagers, around the age of 14 or 15, are more likely to have their preferences considered by the court.
see related question
I believe it is 13-years-old.