Check out
http://www.alllaw.com
In the bottom left corner there is a link for a support calculator. Click on it and then follow the links to child support and then the link for Alabama.
That will give you the actual $$ amount for that state requirements. NOTICE that it will be a suggested amount, the actual support amount can be within a couple hundred dollar range of that, either way.
My husband's lawyer suggested one amount, his ex's lawyer suggested another. The judge took a in the middle approach and set it there. The finally decision is that of the judge.