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Calculation Machine

Fiber Intake Calculator

Daily fibre target and your gap.

Reviewed by the Calculation Machine team · How we check our maths

Your values

ⓘ Live results

Results
Daily fibre target
31 g
Standard guideline
38 g
Your shortfall
13 g
Equivalent apples
2.9
Equivalent cups of black beans
0.9

Quick answer

Adults need roughly 14 g of fibre per 1000 calories — about 25 g for women and 38 g for men.

The formula

Fibre (g) = calories ÷ 1000 × 14

Worked example

Worked example

Using the values the calculator loads with.

Inputs

  • Daily calories2200 kcal
  • SexMale
  • Current fibre intake18 g

Result

  • Daily fibre target31 g
  • Standard guideline38 g
  • Your shortfall13 g
  • Equivalent apples2.9
  • Equivalent cups of black beans0.9

How to use the Fiber Intake Calculator

  1. 1Enter your daily calorie intake.
  2. 2Select your sex for the standard guideline.
  3. 3Enter what you currently eat to see the gap.

Frequently asked questions

Can I get too much fibre?

Above 50 g a day can cause bloating and reduce mineral absorption.

Should I increase gradually?

Yes — add 5 g a week and drink more water.

About this calculator

Why fibre targets are based on calories

US dietary guidance sets fibre at about 14 g per 1,000 kcal eaten, which works out to roughly 25 g a day for many women and 30–38 g for many men. Most adults eat well under that — around 15 g a day.

Fibre helps digestion, keeps you full for longer and is linked to lower risk of heart disease and type 2 diabetes. The calculator turns your calorie intake into a daily target.

Raising fibre without discomfort

  • Increase gradually over two to three weeks to avoid bloating.
  • Drink more water as fibre goes up.
  • Easy swaps: oats for breakfast, wholegrain bread, beans or lentils in soups, fruit with skin on.
  • A cup of cooked lentils has about 15 g of fibre — half a day's target in one food.

Sources

More questions

Can you eat too much fibre?

Very high intakes (well above 50–70 g a day) can cause digestive upset and reduce absorption of some minerals.

Do fibre supplements count?

Yes, but whole foods also bring vitamins, minerals and a mix of fibre types.