Fiber Intake
Calculator
Find a daily fiber target from your calorie intake and your age and sex — then see how far your current intake is from it. Fiber is one of the highest-leverage, most-neglected levers in the diet.
About you
Your daily fiber target
Based on 14 g per 1000 kcal
Target = the higher of 14 g per 1000 kcal and the age/sex Adequate Intake (men <50: 38 g, 50+: 30 g; women <50: 25 g, 50+: 21 g). Increase fiber gradually and with plenty of water — a sudden jump causes bloating. General guidance, not personalized medical or dietetic advice.
How this works
Methodology reviewed July 2026This tool sets a daily fiber target from two references and takes the larger of the two: the 14 grams of fiber per 1,000 calories guideline scaled to your calorie intake, and the age- and sex-specific Adequate Intake. If you enter your current fiber intake, it also shows the gap to close. Fiber is one of the highest-leverage, most-neglected levers in the diet — and on a GLP-1, as total food falls, fiber quietly drops with it.
From calories = (daily kcal ÷ 1000) × 14 g
Adequate Intake (AI):
men <50: 38 g · 50+: 30 g
women <50: 25 g · 50+: 21 g
Target = max(from calories, age/sex AI)
Gap = target − current intake
Sex · Age · Daily calories · Current fiber intake (optional)
Daily fiber target · Calorie-based figure · Age/sex Adequate Intake · Gap to target
- Calorie intake entered reflects your typical daily energy intake.
- The 14 g per 1,000 kcal guideline and the DRI Adequate Intakes apply to generally healthy adults.
- The target is floored at the age/sex Adequate Intake so low-calorie days don't set an unrealistically low goal.
- It is a general target, not personalized medical or dietetic advice.
- It doesn't distinguish soluble from insoluble fiber, which have different effects.
- Individual tolerance and needs vary, especially with GI conditions.
- Increase fiber gradually and with plenty of water — a sudden jump causes bloating and cramping.
- If you have a GI condition or are on a GLP-1 with significant constipation, coordinate changes with your clinician.
References
This calculator is for educational purposes only and is not medical advice, diagnosis, or treatment. Results are estimates based on published formulas and population averages — your individual values may differ. Nothing here is calculated on a server: everything runs in your browser and no data is stored or sent anywhere. Always consult a qualified clinician before making health, medication, or training decisions.