Seems more like a person by person kind of thing. A person's limit can be based off things like gender, weight, age, amount of alcohol, and even how much or how little someone has had to eat prior to drinking. So for example, if a 180 lb male and a 140 lb female go drink for drink, the female is going to "hit her limit" faster.
If you are considering drinking, but haven't figured out your limit (or just don't want to go over your limit) - try doing things like pacing yourself when drinking. You could also alternate each alcoholic beverage with a non-alcoholic one, preferably water to help with hydration (and reduce the chances for a rough morning). Try spending time talking to friends, dancing to music, meeting new people, or listening to whatever music is playing. Give yourself reasons to slow up and enjoy the moment-- not spend it looking down the bottom of a solo cup.
Knowing your limits can be helpful, but knowing how to stay in the blue zone by using the tips above can keep you within your limits and having fun for the long run.