Fiber Supplement Dose Calculator
Find how much fiber supplement to add — in grams and teaspoons — to reach your daily fiber goal after counting the fiber in your food.
How it works
Fiber goal = 14 g per 1,000 kcal · Shortfall = goal − food fiber · Teaspoons = shortfall ÷ fiber per teaspoon
Dietary fiber guidance scales with intake at about 14 g per 1,000 calories, which works out near 25 g/day for many women and 38 g/day for many men. The best fiber comes from food, so this tool subtracts what you already eat and only supplements the gap. Increase supplemental fiber gradually and drink plenty of water — adding a lot at once commonly causes bloating and gas.
Worked example
On a 2,000 kcal diet the goal is 2 × 14 = 28 g/day. Eating 15 g from food leaves a 13 g shortfall. With a psyllium supplement at 5 g per teaspoon, that is 13 ÷ 5 = 2.6 teaspoons — best worked up to over several days rather than added all at once.
Frequently asked questions
How much fiber do I actually need?
The 14 g per 1,000 kcal rule lands most adults around 25–38 g/day. Your calorie intake sets the exact target, which is why this tool starts from calories.
Should I ramp up slowly?
Yes. Jumping to a large fiber dose overnight often causes gas, cramping and bloating. Add a teaspoon at a time over a week or two and increase your water intake.
Is supplement fiber as good as food fiber?
Supplements help close a gap, but whole foods bring a mix of soluble and insoluble fiber plus vitamins and phytonutrients that a single supplement does not.
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Educational estimate, not medical advice. Talk to a doctor, pharmacist or registered dietitian before starting or changing any supplement, especially if you are pregnant, nursing, on medication or managing a health condition.