I just turned 15 and my penis size is 7 inches. How can it get bigger?

You're not fully grown yet. You won't know how big your penis will end up being until you're in your mid 20's. The average flaccid size for a human penis is 3.5 inches, and erect is 5 to 6 inches, so no worries.

The only way your penis can actually get bigger is if it naturally grows more. Give it some time. i agree making ure dick bigger with surgery can be dangerous