Turning calories into a fiber target
Enter the calories you eat in a day and the page converts them into a fiber target in grams. If you know your current intake, add it and the difference is reported as short of or above the target; leave it blank and only the target appears, with current intake marked as not entered. The formula it applied is printed with the results.
The rate used is 14 g per 1,000 kcal (as of October 2026). The current dietary reference figure for fiber is an adequate intake, and it was set on the basis of reduced coronary heart disease risk. The Institute of Medicine (2005) adequate intakes are 38 g a day for men and 25 g for women aged 19 to 50; the European Food Safety Authority treats 25 g a day as adequate for normal bowel function in adults; and Nordic recommendations put the range at 25 to 35 g a day, or about 3 g per MJ. The Dietary Guidelines for Americans use the same 14 g per 1,000 kcal basis.
This page does not look up a recommendation by age or sex, and it does not add up the fiber in individual foods. It is a conversion built on one axis: calories. Reaching the target is not a claim that disease is prevented, and an adequate intake is a population-level figure. Anyone with inflammatory bowel disease or a history of bowel surgery should speak to a clinician before increasing fiber. This result is not medical advice.
Frequently asked questions
It works from calories instead. The current adequate intake is itself set at 14 g per 1,000 kcal, and the gram figures given per age and sex are derived by multiplying that rate by each group’s energy recommendation. Entering the calories you actually eat skips a step.
As a reference, yes. The Institute of Medicine (2005) adequate intakes are 38 g a day for men and 25 g for women aged 19 to 50, with 28 to 29 g in pregnancy and lactation. The European Food Safety Authority treats 25 g a day as adequate for normal bowel function in adults, and Nordic recommendations give 25 to 35 g a day or about 3 g per MJ.
It cannot be put that way. The current figure is an adequate intake set on the basis of reduced coronary heart disease risk, not a guarantee for any individual. What is worth knowing is that actual intake often falls short of half the recommendation.