Fiber Goal Calculator
Find your daily fiber target and a gentle week-by-week plan to reach it.
Your fiber plan
Enter your age and pick a sex to see your target.
- Daily target
- 0 g
- You now
- about 0 g
- To go
- 0 g
Your week-by-week ramp
Easy swaps
- Brown rice for white rice (1 cup cooked): about 2.6 g more.
- Whole-wheat spaghetti for regular (1 cup cooked): about 2.4 g more.
- An apple instead of apple juice (1 medium apple for 1 cup of juice): about 3.9 g more.
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Daily fiber targets for adults
| Age | Women | Men |
|---|---|---|
| 19 to 50 | 25 g | 38 g |
| 51 and up | 21 g | 30 g |
These are the National Academies' Adequate Intakes: 14 g of fiber for every 1,000 calories, at the calories a typical adult in each group eats. Pregnancy and breastfeeding change the numbers, so ask your clinician for yours.
How the calculator works
- Your target is the Adequate Intake for your age and sex. If you enter your calories, it uses the same 14 g for every 1,000 calories that those targets are built on.
- What you eat now is an estimate. Each serving counts as one common food from USDA FoodData Central: 1 medium apple (4.4 g), half a cup of cooked broccoli (2.6 g), 1 slice of whole-wheat bread (1.9 g), half a cup of cooked lentils (7.8 g). Real foods vary, so treat it as a ballpark.
- The ramp spreads your gap evenly over 4 weeks, or fewer if it's only a few grams. MedlinePlus Medical Encyclopedia advises adding fiber gradually over a few weeks (a lot at once can cause gas, bloating and cramps) and drinking plenty of fluids.
Not reviewed by a dietitian yet. Every number here comes from the sources below. A registered dietitian hasn't checked this calculator yet.
Sources
- Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005) , Institute of Medicine, The National Academies Press (accessed Oct 13, 2026)
- FoodData Central (SR Legacy) , U.S. Department of Agriculture, Agricultural Research Service (accessed Oct 13, 2026)
- Fiber , MedlinePlus Medical Encyclopedia, U.S. National Library of Medicine (accessed Oct 13, 2026)