HomeAll ToolsAboutBlog
Nutrition

Fiber Intake Calculator

Calculate your personalised daily dietary fiber target based on age, sex, weight, caloric intake and health goal. Based on USDA and EFSA guidelines. Supports kg and lbs.

Fiber Intake Calculator

Result in grams per day

Unit System
—
Daily Fiber Goal

The USDA bases fiber recommendations on caloric intake: 14 g per 1,000 kcal consumed. EFSA recommends a flat 25 g/day for adults. This calculator blends both approaches and adjusts upward for specific goals like weight loss (higher satiety) or cardiovascular health (higher soluble fiber target). Most people fall far short of their daily fiber needs.

Daily Fiber Requirements by Age & Sex (USDA/EFSA)

GroupAgeGoal (g/day)Source
Children4–825 gUSDA DRI
Girls / Boys9–1326–31 gUSDA DRI
Teen females14–1826 gUSDA DRI
Teen males14–1838 gUSDA DRI
Adult women19–5025 gUSDA / EFSA
Adult men19–5038 gUSDA DRI
Women 51+51+21 gUSDA DRI
Men 51+51+30 gUSDA DRI
Pregnant womenAny28 gUSDA DRI

Why Dietary Fiber is Essential for Health and Performance

Dietary fiber — the indigestible portion of plant foods — plays a critical role in digestive health, cardiovascular function, blood sugar regulation, and body weight management. Soluble fiber (oats, beans, psyllium) slows carbohydrate absorption and reduces LDL cholesterol. Insoluble fiber (whole grains, vegetables) adds bulk to stool, preventing constipation and supporting a healthy gut microbiome. High-fiber diets are linked to a 16–33% lower risk of colorectal cancer, significant reductions in cardiovascular risk, and better glycaemic control in diabetics. For physique athletes, adequate fiber promotes gut health, reduces bloating with proper timing, and enhances satiety during a calorie deficit.

Frequently Asked Questions

USDA: 14 g per 1,000 kcal (≈25 g for women on 2,000 kcal, ≈38 g for men on 2,700 kcal). EFSA recommends 25 g/day flat for all adults. Most adults only consume 15–17 g/day. Increasing to 25–38 g/day is associated with significant health benefits including lower cardiovascular risk, better blood sugar control, and improved gut health.
Soluble fiber dissolves in water to form a gel, slowing digestion, blunting blood sugar spikes, and binding cholesterol. Found in: oats, beans, lentils, apples, barley, psyllium husk. Insoluble fiber doesn't dissolve — it adds bulk to stool and speeds transit through the colon. Found in: whole wheat, bran, nuts, and most vegetables. A balanced diet naturally provides both types.
Very high fiber intake (>70 g/day) without adequate hydration can cause bloating, gas, cramping, and constipation. Extremely high fiber may also reduce the absorption of iron, zinc, calcium, and magnesium. Increase fiber intake gradually — add 5 g per week — and drink at least 2 litres of water daily. For most people, even reaching 40–50 g/day from whole foods is challenging and generally safe.
Highest fiber foods per 100 g: chia seeds (34 g), flaxseeds (27 g), psyllium husk (70 g), split peas cooked (8 g), lentils cooked (8 g), black beans cooked (8.7 g), oats (10 g dry), avocado (6.7 g), edamame (5 g), broccoli (2.6 g), peas (5.7 g), quinoa (2.8 g). Eating a variety of legumes, whole grains, vegetables, and seeds is the most sustainable approach.

Related Calculators

Macro CalculatorCalculate daily protein, carb, and fat targets.Calculate → Food Calorie CalculatorLook up fiber and calories in any food.Calculate → Calorie Deficit CalculatorCalculate the deficit needed for fat loss.Calculate → Carb CalculatorDaily carb targets for any goal.Calculate →