Is this a good vocal range?

Okay, so I can sing (in a chest voice, so "belt") from C3 to the D above C5. (So slightly over a 3 octave range for belting) but then I can sing in head voice (or falsetto) to nearly C6, not quite, more like the A or B before C6. So almost 4 octaves for a range. I am 16, so I don't know if that is considered good for like musical theater, or if that would be good for musical theater, or if I need to improve my range some more. :)