Although it is JavaScript based, Google Charts has a couple of options to make your charts entirely in PHP. You can either use server-side code (in our case PHP) to get the data, or get one of the open-source wrappers to do it for you.

Source: 4 Best Chart Generation Options with PHP Components – SitePoint

Need to generate charts for the baseball-handbook.com website and looking into php options.  Google seems like the simplest solution right now.  The above site breaks down each option nicely.

Here’s more info about Google Charts.