Fiber Needs Calculator
Estimate your daily dietary fibre target from your calorie intake using the 14 grams per 1,000 kcal guideline, with age and sex reference amounts.
How it works
Fibre (g) = calories ÷ 1,000 × 14
The Institute of Medicine recommends about 14 g of dietary fibre for every 1,000 kcal consumed, a target linked to lower risk of heart disease. That translates to roughly 25 g a day for adult women and 38 g for adult men, dropping somewhat after age 50 as calorie needs fall. Most people eat only about half of this, so gradually adding whole grains, legumes, fruit and vegetables — with plenty of water — closes the gap.
Worked example
For a 2,000 kcal diet: 2,000 ÷ 1,000 × 14 = 28 g of fibre a day. That sits between the reference amounts of 25 g for women and 38 g for men.
Frequently asked questions
How much fibre do I need per day?
About 14 g per 1,000 calories, which works out to roughly 25 g for women and 38 g for men under 50, and a little less after 50. On 2,000 kcal that is about 28 g.
Can I eat too much fibre?
Very high intakes increased suddenly can cause bloating, gas and cramping, and may hinder absorption of some minerals. Increase fibre gradually and drink enough water.
What foods are high in fibre?
Beans and lentils, whole grains, bran, berries, pears, broccoli and nuts are among the richest sources. Whole plant foods generally beat refined ones.
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Educational estimate using standard published formulas — not medical, dietary or nutritional advice. Individual needs vary with health status, medication and activity; consult a qualified clinician or dietitian before making changes.