Most people eat far less fiber than they need. This free calculator shows your daily fiber target based on your age and sex, using the adequate intakes set by the U.S. Institute of Medicine. If you add your daily calories, it also shows the 14 grams per 1,000 calories guide. A table of everyday foods shows how to get there.
Adequate fiber intake by age and sex
| Group | Fiber per day |
|---|---|
| Children 1 to 3 | 19 g |
| Children 4 to 8 | 25 g |
| Girls 9 to 13 | 26 g |
| Boys 9 to 13 | 31 g |
| Girls 14 to 18 | 26 g |
| Boys 14 to 18 | 38 g |
| Women 19 to 50 | 25 g |
| Women 51 and older | 21 g |
| Men 19 to 50 | 38 g |
| Men 51 and older | 30 g |
The 14 g per 1,000 calories guide
The adequate intakes were built from a simple idea: about 14 grams of fiber for every 1,000 calories you eat. At 2,000 calories that is 28 grams, which is also the Daily Value printed on food labels. If you eat much more or less than average, the calorie-based figure may suit you better, so the calculator shows both when you enter your calories. If you used our calorie calculator first, your number is filled in for you.
Why fiber matters
Fiber is the part of plant foods your body does not digest. It keeps digestion regular, helps lower cholesterol and steady blood sugar, feeds helpful gut bacteria and helps you feel full. Diets high in fiber are linked with a lower risk of heart disease and type 2 diabetes. Surveys suggest the average adult in the United States eats only about 15 grams a day, which is why the calculator shows how far that is from your target.
Easy ways to reach your target
| Food | Fiber (approx.) |
|---|---|
| Lentils, cooked, 1 cup | 15 g |
| Raspberries, 1 cup | 8 g |
| Black beans, cooked, ½ cup | 7.5 g |
| Chickpeas, cooked, ½ cup | 6 g |
| Pear with skin, 1 medium | 5.5 g |
| Avocado, ½ fruit | 5 g |
| Broccoli, cooked, 1 cup | 5 g |
| Oatmeal, cooked, 1 cup | 4 g |
| Almonds, 1 ounce | 3.5 g |
| Whole-wheat bread, 1 slice | 2 g |
- Start the day with oats, whole-grain cereal or fruit. See healthy breakfast ideas.
- Add beans or lentils to soups, salads and rice dishes.
- Choose whole fruit over juice, and snack on nuts, fruit or raw vegetables: healthy snacking ideas.
- Swap white bread, rice and pasta for whole-grain versions.
- Increase slowly, by 3 to 5 g every few days, and drink water. Going from low to high overnight can cause gas and bloating.
For the full picture, read our guide to fiber, the everyday nutrient most people miss. You can also balance your plate with the macro calculator.
Check with a professional if…
- You have inflammatory bowel disease, a bowel narrowing, or have had bowel surgery. A different fiber plan may be needed.
- You have frequent constipation, diarrhea, blood in the stool or unexplained weight loss.
- You are pregnant or breastfeeding and want a personal target.
Frequently asked questions
How much fiber should I eat a day?
For adults it ranges from about 21 to 38 grams a day depending on age and sex, or about 14 grams per 1,000 calories. Use the calculator above for your own target.
Why is the fiber target lower for older adults?
The adequate intakes are based on the 14 g per 1,000 calories rule, and older adults usually eat fewer calories. Many older adults still eat well below the target.
Can I eat too much fiber?
Very large, sudden increases can cause gas, bloating and cramps. Raise your intake gradually with plenty of fluids. Most people are far below the target, not above it.
Do fiber supplements count?
They can help some people, but whole foods also give vitamins, minerals and other nutrients. Food first is the usual advice. Ask a pharmacist or doctor about supplements.
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This calculator provides general estimates for healthy adults and is for information only. It is not medical advice and does not replace a conversation with a qualified healthcare professional. Read our disclaimer and editorial policy.