How much should I tip a server whose restaurant has a service charge?

As a bartender in a restaurant myself, whenever I eat out I always tip. The only thing that confuses me is the service charge in some places; I know not all of that goes to your server.|||At least 10%, I usually give them 15 % due to the charge being there already"|||Depends how much of a per cent you think goes to the server. Regular tipping is 15% I believe. If you think they get 2% for example, tip them 13%. ^_^