How much fiber should I eat per day?

A common adult reference is 14 grams of fiber per 1,000 calories, with practical daily targets often around 25 to 38 grams depending on age and sex.

Can fiber supplements replace whole foods?

Supplements such as psyllium can help some people, but vegetables, fruit, beans and whole grains also provide vitamins, minerals and food structure.

Can too much fiber be a problem?

There is no single universal upper limit, but many people notice bloating, cramps, diarrhea or constipation when intake rises quickly or fluids are low.

Fiber Calculator

Estimate a daily fiber target from age, sex, calorie intake and goal, then compare it with a typical current diet pattern.

Fiber planning inputs

Sex

Male

Female

Age

Daily calories (cal/day)

Goal

Current diet pattern

Daily fiber intake target

This calculator combines the common 14 grams per 1,000 calories approach with adult age-and-sex reference values, then shows a practical daily target.

F_{e n er g y} = \frac{c a l or i es}{1000} \times 14

Calorie-scaled fiber target.

F_{t a r g e t} = max (F_{e n er g y}, F_{se x, a g e}, F_{g o a l})

The result uses the larger of the calorie-scaled, age/sex and selected-goal targets.

Increase gradually

Higher fiber intake can cause bloating or stool changes when raised quickly. Digestive disease, diabetes, pregnancy and medical diets need individualized advice.

Soluble and insoluble fiber

Type	Common sources	Planning note
Soluble fiber	Oats, beans, apples, citrus, psyllium	Can support fullness and be part of glucose or LDL planning.
Insoluble fiber	Bran, whole grains, vegetables, fruit skins	Often supports stool bulk when fluids are adequate.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

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