Fiber Intake Calculator

Daily fibre target by age and sex. Free, private and instant.

How to use the Fiber Intake

  1. Choose sex: Male or Female.
  2. Enter age.
  3. Enter daily calories (optional) (kcal) - optional.
  4. Press Calculate to get an instant result with a colour scale, chart and plain-English explanation.

About the Fiber Intake

The fibre intake calculator gives your daily target based on age and sex using the Institute of Medicine adequate intake. Most adults need 21 to 38 g a day, and most eat far less.

Also known as: fibre calculator, how much fiber per day, daily fiber needs, fiber requirement calculator.

Worked example

Daily fibre target: 38 g/day (Adequate intake (male)). Aim for about 38 g of fibre a day. Add it gradually and drink plenty of water.

Formula and cut-offs

Adequate intake: men 19-50 38 g, men 51+ 30 g, women 19-50 25 g, women 51+ 21 g. Alternative rule: 14 g per 1,000 kcal.

Frequently asked questions

How much fibre do I need a day?

Roughly 25 g for women and 38 g for men under 50, and a little less after 50.

What foods are high in fibre?

Lentils, beans, oats, whole grains, vegetables, fruit with skin, nuts and seeds.

Can too much fibre cause problems?

Adding fibre too fast can cause gas and bloating. Increase gradually and drink enough water.

What is the daily fibre target for a 30-year-old man?

Daily fibre target: 38 g/day (Adequate intake (male)). Aim for about 38 g of fibre a day. Add it gradually and drink plenty of water. Enter your own numbers above for a personal result.

Sources and references

Written and checked by the MediHub editorial team against the sources above. Read how we build and review our calculators.

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Last updated . This calculator is for education only and is not medical advice. See the medical disclaimer.