How should i tell my best guy friend that i really like him?

He's been my best guy friend since 5th grd and now were going into 8th grd. In 5th grd we sat next to eachother in class and every time we had a group project thing me n him would mostly always pair up. In 6th grd our classes were right next to eachother and at reccess we would play handball. And once he went to the movies with me my bro and my mom. Now we just graduated 7th grd and we hang out a lot more. He wants to come over more often. Is this a sign that he likes me?? How should I tell him I like him? And yes he's single :) any advice or help would be appreciated. I'm small for my age I'm 13 and currently 4'8 and he's also 13 and about 5'2