Can someone please explain this? i'm still confused about this 14g fiber for every 1, 000 cals. for example, if i consumed 2, 205 cals in a day and 28g fiber, is that not enough then? i don't get it

Close enough: 25gm of fiber a day should meet most women's dietary needs. The institute of medicine formula you are quoting is just a general guideline. (2, 115cal * 14gm/1, 000cal = 29.6gm of fiber).

Rough estimate: This based on recommendations from the institute of medicine and is a general rule of thumb, not a strict number. If you consume 2, 205 calories then you should aim for 30 grams of fiber per day. If it is a little more on some days and a little less on other days it will even out. If you are consistently low, however, you should probably aim for more high-fiber lower-calorie foods.