Fiber Intake Calculator
Find your recommended daily fiber from your calories.
Results update as you type.
This calculator provides estimates based on population research. Results are not medical advice. Consult a qualified healthcare provider before making health or nutrition decisions.
How it works
Most people fall well short of the fiber they need, and this calculator shows your target and your shortfall. You enter your daily calorie intake, and optionally your current fiber, and it returns your recommended daily fiber and the gap between that and what you eat now. The recommendation follows the widely used guideline of 14 grams of fiber per 1,000 calories, so someone eating 2,000 calories a day should aim for about 28 grams. This works out close to the commonly cited targets of roughly 25 grams a day for women and 38 for men. Fiber is the part of plant foods your body cannot digest, and it plays several important roles: it promotes regular digestion, feeds beneficial gut bacteria, helps control blood sugar by slowing carbohydrate absorption, lowers cholesterol, and increases fullness, which supports weight management. Despite these benefits, average intake in many countries is only about half the recommended amount. Good sources include whole grains, beans and lentils, fruits, vegetables, nuts, and seeds. Increase fiber gradually and drink plenty of water to avoid digestive discomfort. A positive fiber gap tells you how many grams to add; aim to close it by building meals around whole plant foods. Enter your calories to find your recommended fiber intake and gap.
Recommended fiber = 14 g × (daily calories / 1,000)
Dietary guidelines set fiber needs at about 14 grams per 1,000 calories consumed, so the recommended amount scales with your energy intake. Multiply 14 by your daily calories divided by 1,000. The fiber gap is that recommendation minus your current intake, showing how much more fiber you need each day.
Source:Dietary Guidelines for Americans (14 g/1,000 kcal)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter daily calorie intake.
- 2
Adjust the options
Adjust current fiber intake if they apply — sensible defaults are already set.
- 3
Read your result
Recommended daily fiber updates instantly as you type — no button to press.
Frequently asked questions
How much fiber do I need per day?
A common guideline is 14 grams of fiber per 1,000 calories, so a 2,000-calorie diet calls for about 28 grams daily. This aligns with the frequently cited targets of roughly 25 grams for women and 38 grams for men. The calculator personalizes the amount to your actual calorie intake rather than a one-size-fits-all number.
Why is fiber important?
Fiber supports digestive regularity, feeds beneficial gut bacteria, slows carbohydrate absorption to steady blood sugar, helps lower cholesterol, and increases fullness to aid weight control. Higher fiber intake is linked to lower risk of heart disease, type 2 diabetes, and certain cancers, making it one of the most beneficial and under-consumed parts of the diet.
What foods are high in fiber?
Excellent sources include beans, lentils, and other legumes, whole grains such as oats and brown rice, fruits like berries, pears, and apples, vegetables, nuts, and seeds. Choosing whole plant foods over refined ones is the simplest way to raise fiber. Beans and lentils are especially dense sources, often providing many grams per serving.
Can I get too much fiber?
Very high fiber intake, especially if increased suddenly, can cause bloating, gas, cramping, or constipation, and in extreme cases may reduce absorption of some minerals. Increase fiber gradually over a couple of weeks and drink plenty of water to let your digestive system adjust. For most people, eating too little fiber is a far more common problem than too much.
How do I close my fiber gap?
Add fiber-rich foods to meals you already eat: beans in a salad or soup, berries or ground flaxseed in breakfast, whole-grain instead of white bread, and vegetables at lunch and dinner. Snacking on fruit, nuts, or seeds also helps. Spreading fiber across the day and pairing it with water makes closing the gap comfortable and sustainable.