Daily Fiber Calculator
How many grams of fiber to aim for — and the plant foods that get you there fast.
Your details
Plant foods to hit 25 g
Grams of each food (as eaten) that would supply your full daily target on its own. In practice, combine 3–5 sources across the day.
- Chia seeds74 g(34 g fiber / 100 g)
- Flaxseeds93 g(27 g fiber / 100 g)
- Split peas313 g(8 g fiber / 100 g)
- Lentils313 g(8 g fiber / 100 g)
- Black beans313 g(8 g fiber / 100 g)
- Chickpeas313 g(8 g fiber / 100 g)
- Avocado357 g(7 g fiber / 100 g)
- Raspberries357 g(7 g fiber / 100 g)
- Broccoli (cooked)833 g(3 g fiber / 100 g)
- Sweet potato833 g(3 g fiber / 100 g)
- Oats (cooked)1,250 g(2 g fiber / 100 g)
- Apple (with skin)1,250 g(2 g fiber / 100 g)
How this is calculated
Quick mode uses the Institute of Medicine Adequate Intake values: 25 g/day for adult women (21 g after 50) and 38 g/day for adult men (30 g after 50).
From calories applies the more precise IOM guideline of 14 g of fiber per 1,000 kcal. This scales fiber intake to your actual food volume — larger eaters need more fiber, smaller eaters less.
Ramp gradually. If you currently eat less than 20 g/day, increase by 5 g per week and drink an extra glass of water each time you add fiber. Your gut microbiome takes 2–4 weeks to adapt.
Frequently asked
How much fiber do I need per day?+
The Institute of Medicine recommends 25 g/day for adult women (21 g after 50) and 38 g/day for adult men (30 g after 50). A more precise target is 14 g of fiber per 1,000 kcal you eat.
Is more fiber better?+
Up to a point. Adults on plant-forward diets often reach 40–60 g/day and thrive. Above 70 g may cause bloating in some people — increase gradually (5 g per week) and drink plenty of water so your gut adapts.
What are the highest-fiber plant foods?+
By density: chia seeds, flaxseeds, and split peas. By volume: lentils, black beans, chickpeas, raspberries, and avocado. A day that includes legumes, seeds, whole grains, and 2–3 servings of fruit or vegetables usually clears 35 g without effort.
Does fiber help with weight loss?+
Yes — soluble fiber slows gastric emptying and increases satiety, and each gram of fiber effectively subtracts calories from your net intake. Every well-designed weight-loss study on plant diets sees people eat less spontaneously as fiber rises.
Related tools
References
- National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press, 2005.
- U.S. Departments of Agriculture and Health and Human Services. Dietary Guidelines for Americans, 2020 –2025.
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central. USDA, 2024.
Educational estimates only, not medical advice. Individual needs vary — consult a physician or registered dietitian.