Calculator Inputs
Example Data Table
| Profile | Calories Used | Demographic Target | Energy Target | Recommended Target | Current Intake | Fiber Gap |
|---|---|---|---|---|---|---|
| Female, 32 years, moderately active | 2100 kcal | 25.0 g | 29.4 g | 29.4 g | 18.0 g | 11.4 g |
| Male, 45 years, very active | 2800 kcal | 38.0 g | 39.2 g | 39.2 g | 30.0 g | 9.2 g |
| Female, 61 years, lightly active | 1700 kcal | 21.0 g | 23.8 g | 23.8 g | 24.0 g | -0.2 g |
Formula Used
1) Weight conversion
Weight in kg = pounds × 0.45359237
2) Height conversion
Height in cm = inches × 2.54
3) Basal Metabolic Rate
Male BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Female BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
4) Estimated daily calories
TDEE = BMR × activity factor
5) Energy-based fiber target
Fiber target = (daily calories ÷ 1000) × 14
6) Demographic target
Female 18–50 = 25 g/day, Female 51+ = 21 g/day
Male 18–50 = 38 g/day, Male 51+ = 30 g/day
7) Final recommended fiber target
Recommended target = higher of demographic target and energy target
8) Fiber gap
Fiber gap = recommended target − current fiber intake
9) Per meal goal
Per meal goal = recommended target ÷ meals per day
How to Use This Calculator
- Enter your age, sex, weight, and height.
- Select your weight and height units.
- Choose whether to estimate calories or enter them directly.
- Pick your daily activity level if using estimated calories.
- Enter your current average fiber intake in grams per day.
- Set how many meals you usually eat each day.
- Press the calculate button to view your target and gap.
- Use the chart and export buttons to save your results.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates a practical daily fiber target using age, sex, and calories. It also compares your current intake with that target and shows how much fiber per meal may help you stay on track.
2) Why are there two fiber targets?
One target comes from age and sex guidance. The other uses the calorie rule of 14 grams per 1,000 calories. The calculator uses the higher value for a more protective planning target.
3) Why estimate calories from body data?
Some users do not track calories closely. Estimating calories from body size, age, sex, and activity provides a useful planning value for the energy-based fiber formula.
4) Can I use my own calorie intake instead?
Yes. Choose custom calorie mode and enter your average daily calories. The calculator will then use your number instead of the estimated total daily energy expenditure.
5) What does fiber gap mean?
Fiber gap is the difference between your recommended target and your reported current intake. A positive gap means you need more fiber. A negative gap means your intake is already above target.
6) What does per meal goal show?
It divides your recommended daily target by the number of meals you eat. This creates an easy meal-by-meal planning number instead of one large total for the entire day.
7) Is more fiber always better?
Not always. Large jumps in fiber may feel uncomfortable. It is usually better to increase intake gradually, spread it across meals, and keep fluid intake appropriate for your routine.
8) Who should use this tool carefully?
People with digestive disorders, special medical diets, or clinician-directed nutrition plans should treat this as an educational planning tool and follow personal medical guidance when needed.