Fiber Intake Calculator
Find your recommended daily fiber intake, in grams, for adults.
How this works
Recommended fiber intake is set as an amount per 1,000 calories eaten (14 grams per 1,000 calories, under the Dietary Guidelines for Americans), then translated into flat gram targets by age and sex based on typical calorie needs for each group -- which is why the target drops somewhat for older adults, whose average calorie needs are lower, not because fiber itself matters less as you age.
Age bands and figures here come from Cleveland Clinic’s own reference table: 28g/day for women 19-30, 25g for women 31-50, 22g for women 51+; 34g/day for men 19-30, 31g for men 31-50, 28g for men 51+.
If you want a more personalized number than the age-band figures above, the Calorie Calculator can estimate your own actual daily calorie needs, which you can then scale by the same 14g-per-1,000-calories rule this tool uses.
Frequently asked questions
Why does the recommended amount decrease with age?
The 14-grams-per-1,000-calories rule this is based on scales with how much you eat, not a separate “fiber needs less as you age” rule -- older adults typically need fewer total calories, so the fiber target calculated from that lower calorie level comes out lower too.
Why do men need more fiber than women?
Same reasoning as the age difference: the target is calculated from typical calorie needs, and men’s average calorie needs run higher than women’s at the same age, which scales the 14g-per-1,000-calories rule up to a higher gram figure.
Are most people actually getting enough fiber?
No -- only about 5% of men and 9% of women in the US meet the recommended daily fiber intake. Average actual intake is closer to 14-16 grams a day, well under most people’s target.
What if I eat significantly more or fewer calories than average?
Scale the 14-grams-per-1,000-calories rule to your own intake instead of using the flat age/sex figure -- someone eating 2,500 calories a day would target roughly 35 grams of fiber, regardless of what a general age-based table suggests.