Fiber Intake Calculator
Find your daily fiber target from your calorie intake, using the 14 g per 1,000 kcal rule.
How it works
fiber grams = calories ÷ 1000 × 14 · IOM: men 38 g (≤50) / 30 g, women 25 g (≤50) / 21 g
The Institute of Medicine derived its fiber recommendation as 14 grams per 1,000 calories, the level associated with the lowest heart-disease risk in the underlying studies. That scales fiber to how much you eat. The fixed age-and-sex targets are the same guidance expressed as round numbers.
Worked example
On 2,000 kcal: 2,000 ÷ 1,000 × 14 = 28 g of fiber per day — matching the IOM target for an adult woman and a bit below the 38 g target for a younger man.
Frequently asked questions
How much fiber do I need daily?
About 14 g per 1,000 calories, which works out to roughly 25 g/day for women and 38 g/day for men under 50. Most adults eat only about half that.
How do I get more fiber?
Build meals around whole grains, beans and lentils, fruit with the skin, vegetables, nuts and seeds. Increase gradually and drink more water to avoid bloating.
Soluble vs insoluble fiber — does it matter?
Both help. Soluble fiber (oats, beans, apples) slows digestion and helps blood sugar and cholesterol; insoluble fiber (whole grains, vegetable skins) adds bulk and aids regularity. A varied plant-rich diet supplies both.
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Educational estimate, not medical or dietary advice.