How do you know what size baseball bat to get?

I'm 5'5, 14 y/o, and going into high school. I weigh 114 lbs. I am trying out for high school team and need a good bat. I am currently going through a growth spurt and my voice hasn't changed. What sized baseball bat should I get? Is there a way to calculate it?|||take a bat and hold it straight out to your side. if you can hold it up without straining then it will be a good weight. if its too easy or too much then try diff. ounces until you find a good one.as far as length a 32-34 should be perfect. if its too long you can always choke up.|||Find a comfortable wieght for u. You want a bat that is light not heavy. Your only fourteen and you dont need a huge homerun hitting bat.|||ask someone at a sports store. If its walmart or something, dont ask anybody but if you swing it around and it feels alright, then go for it.|||30 oz and somewhere around 32 to 34 inches long, will help you grow into it|||Since you play, take note of the size and weight of the bat(s) which give you the best results. Then get one slightly heavier. Work on your strength and you'll be fine.