Some people are really insecure about their number. Other people are insecure about how often they are doing it. If you always have that question in your mind as to whether or not you do it as much as your peers, FEAR NOT. Someone has created a calculator to let you know. Yep. This exists.
Slate.com has created this sex calculator based on info from the General Social Survey-- which is a self-reported survey. If you are curious, click the link and test it out.