16 year old penis 4,4inches long when erect ? is this average size ?

Yes: This is in the range of normal, and you will likely continue to grow.

Slightly less: Average penis size your age while erect is about 5.5 inches. Do not worry about size. Be happy with who you are, learn to love your body

Not done growing: An unerect penis in late adolescence is approximately 4 inches long. A fully erect adult sized penis is typically between 5-6 inches long. You are not far off and you're not done growing by any means! Once you reach full maturity in your early 20's I would expect that you will have a longer penis than you do know and you're already making way towards the "average adult male." Don't worry too much!