Everyone’s body is at least a bit different (unless you have an identical twin), but even so we are all very similar in how our bodies look with different body fat percentages. So for some fitness motivation I give you this excellent chart of body fat % ranges, for men and women, with pictures of how those body types look at each level.
Levels I consider acceptable, based on the above photos, are essentially the top row of each for men or women. Beyond that you are fat, and that’s the plain, simple, and brutal truth. Really women should be in the under 18% body fat range to look fit and men should be under 10% for the equivalent fit look if they have some decent muscle mass. Last I checked I was at 7.5%