I sweat more than average meaning I need to drink tons of water and i have a pretty high salt requirement. Some days I just feel weak and tired and it's actually because of too little salt in my diet. That's usually only on hot summer days though.
I don't know how much I need, but how much I eat is probably about average, which means it's probably too much. Yet when I got my blood pressure checked the nurse asked me if I was on a low-salt diet because my blood pressure was so low.