Fiber Intake Calculator

Calculate your recommended daily fiber intake for optimal digestive and cardiovascular health

Your Information

Rule of thumb: 14g fiber per 1000 calories. Calculate TDEE

How It Works

Calculation Methods

Age/Gender Based (Adequate Intake):
  • Adult men (19-50): 38g/day
  • Adult women (19-50): 25g/day
  • Men 51+: 30g/day
  • Women 51+: 21g/day
Calorie-Based (Alternative):
Fiber (g) = Calories / 1000 × 14

Example: 2000 calories = 28g fiber

Types of Fiber

Soluble Fiber (25-30% of total):

Dissolves in water, forms gel. Benefits: lowers cholesterol, slows glucose absorption

Sources: Oats, beans, apples, carrots, barley

Insoluble Fiber (70-75% of total):

Doesn't dissolve. Benefits: promotes regularity, prevents constipation

Sources: Whole grains, nuts, vegetables, wheat bran

Frequently Asked Questions

What are the benefits of fiber?

Fiber promotes digestive health, prevents constipation, lowers cholesterol, regulates blood sugar, supports weight management (increases satiety), reduces risk of colon cancer, heart disease, and type 2 diabetes. Most people consume only 15g/day - less than half the recommendation.

How do I increase fiber intake safely?

Increase gradually (add 5g per week) to avoid bloating and gas. Drink plenty of water (2-3 liters/day) as fiber absorbs water. Start with whole grains for breakfast, add beans to lunch, snack on fruits/nuts, include vegetables with dinner.

Can I take fiber supplements?

Yes, but whole foods are preferred. Supplements (psyllium, methylcellulose, inulin) can help reach targets but lack nutrients and phytochemicals from whole foods. Use supplements as a temporary boost, not a replacement for dietary fiber.

Why do I feel bloated when I eat more fiber?

Gut bacteria ferment fiber, producing gas. This is normal and temporary. Increase fiber slowly, drink more water, and stay active. Bloating usually resolves in 1-2 weeks as gut microbiome adapts. Soluble fiber causes more gas than insoluble.

Is too much fiber harmful?

Very high fiber (>70g/day) can cause bloating, diarrhea, and mineral absorption issues. Stick to 25-40g/day for adults. Balance soluble and insoluble types. Excessive fiber supplements without adequate water can cause intestinal blockage - rare but serious.

References & Sources

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Dietary Guidelines for Americans

USDA and HHS official dietary fiber recommendations

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Fiber Calculator - Calculator.net

Comprehensive fiber intake guidelines and food sources

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Mayo Clinic - Dietary Fiber: Essential for a healthy diet

Evidence-based guide to fiber benefits and sources

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Health benefits of dietary fiber - PMC

Nutr Rev. 2009 Apr; 67(4): 188–205