Hi there.
Once you experience puberty--the process of sexual maturation--your penis will grow into its adult size. This may take awhile, so be patient. Generally, signs of puberty include increase in height, deepening voice, increase in body and facial hair, and increase in testicle size. Puberty happens at different ages, so don't worry if some of your friends have experienced it earlier than you. Dr. J
Listen buddy, there are things on the market today that you will discover in time, that will increase the size, you are still in the growing stage just cool it for now.
your 13. you shouldn't be worried about the size of your penis just yet.. sagapu is correct. we don't worry about the size of the man's penis it IS mostly how they use it.. so relax. you have plenty of time to "grow". i haven't been with any man that hadn't "matured" in that area. just remember when it comes time for you to become sexually active to read a few books on how to please a woman. that way if your a little self conscious you'll know what to do and don't let her see you being self conscious. women like a man to know how to use it correctly.
Hope this helps!
listen kid , eat your vegatables dont smoke , exercise stay healthy drink milk and you will fill up fine reagardless ... its not about size its about how you use it belive it or not women dont care about that and if she wont date you for your size she doesnt deserve to be with you ..