I am wanting to add a roof (shingled) over my patio. Can I have a span of 16' with 2x12's and 16" centers?

my patio is 25' across and 15' deep - i'd like to have a shingled roof put over it. I would like to use the 2x12's connected to the house at 10' in height and go out 16' (1' over hang) where it would be 8' in height. Is this 15' span too much?