How do I get my puppy (english bulldog) to stop barking when I leave for work?

My puppy is 3 months old but he has been with me for over a week now. He is doing great on potty training and sleep in his crate all night till I let him out. When I come home I can hear him barking and we live in an apartment. How long do they bark for do they tire themselves out and just stop? Any advice to help them not stress when nobody is home?