Food fiber calculator
Pick the foods you ate and the serving size. The calculator adds up your fiber in grams, with every number from USDA FoodData Central.
Your foods
- Oatmeal4g
- Raspberries8g
- Lentils15.6g
Total fiber
27.6grams
That is 110% of a 25 gram goal. You are there.
Add it up every day with Grove
This page has 50 foods and forgets your list when you leave. Grove searches the full USDA database and keeps your day. On iPhone, iOS 18.0 or later.
How do you calculate the fiber in food?
Find the grams of fiber in one serving, multiply by how many servings you ate, and add the foods together.
- Oatmeal, 1 cup, cooked: 4 grams
- Raspberries, 1 cup: 8 grams
- Lentils, 1 cup, cooked: 15.6 grams
Those three foods add up to 27.6 grams. That is more than the 25 gram guideline for women and most of the 38 gram guideline for men.
If you weighed your food, use the fiber per 100 grams instead. Multiply the weight you ate by that number and divide by 100. Cooked lentils have 7.9 grams of fiber per 100 grams, so 150 grams of lentils has about 11.9 grams.
How to use this calculator
- Search for a food, or tap one of the suggestions.
- Pick the serving size that matches what you ate.
- Change the number in front if you had more or less than one serving.
- Read your total at the bottom, next to a 25 or 38 gram goal.
Not sure what your goal should be? The fiber calculator works it out from your age, sex, and calories. To look up one food on its own, use the fiber library.
Questions
How do you calculate the fiber in food?
Find the grams of fiber in one serving, multiply by how many servings you ate, and add the foods together. For example, oatmeal (1 cup, cooked) has 4 grams, raspberries (1 cup) has 8 grams, lentils (1 cup, cooked) has 15.6 grams. Together that is 27.6 grams.
How do I work out fiber from a weight in grams?
Multiply the weight you ate by the food's fiber per 100 grams, then divide by 100. Cooked lentils have 7.9 grams of fiber per 100 grams, so 150 grams of lentils has about 11.9 grams of fiber.
Where do these fiber numbers come from?
Every number comes from USDA FoodData Central, the food composition database run by the U.S. Department of Agriculture. The data on this page was pulled on October 8, 2026. Nothing is estimated.
How much fiber should my foods add up to in a day?
The Institute of Medicine sets 25 grams a day for women and 38 for men up to age 50, then 21 and 30 after that. The calculator lets you compare your total against 25 or 38 grams.
Does this calculator save my food list?
No. The list lives in your browser tab and is gone when you close or reload the page. Nothing you pick is sent anywhere.
What if my food is not in the list?
This page covers 50 common foods. For a packaged food, read Dietary Fiber on the Nutrition Facts label and multiply by your servings. The Grove app searches the full USDA database.
Source: USDA FoodData Central, data pulled October 8, 2026. Daily guidelines from the Institute of Medicine Dietary Reference Intakes. Last reviewed .
Track your fiber intake with Grove
Search real foods, hit your daily goal, and build a gut health habit. On iPhone, iOS 18.0 or later.