Years ago most boys were potty trained by 18 months to 2 years of age.
Now the average age for a boy to potty train is between 2 and half to 3 years old and sometimes as old as 4 years old before the boy will potty train.
A boy should be given the opportunity to at least potty train by 18 months of age because some boys are ready by 18 months of age to potty train.
If the boy doesn't seem interested in the potty at 18 months then try again once the child reaches 2 to 2 and half years of age before trying again with potty training.
It's best to skip the training pants and use underwear since the child will feel wet when they go pee in their pants and want to go to the potty.
A boy should be out of diapers completely by age 4 unless the child has something wrong with them preventing them from potty training.