Direct value
An entered body-fat percentage is accepted only within a plausible range.
Verifiable calculation method
How calorie and macronutrient targets are calculated.
NUTRIMI keeps numerical calculation separate from artificial intelligence: metabolism, activity, goal and grams of protein, carbohydrate and fat come from deterministic rules. The steps, formulas, required data and limitations are published here.
- Technical authorDiego Russo
- Verified2 August 2026
- Production codeRules checked in the implemented calculator
- Primary sourcesPubMed, EFSA, EUR-Lex, NIH
Direct answer
From profile to target in four steps.
For a non-pregnant adult, the general pathway uses age, weight, height, recorded sex, activity level and goal. Pregnancy and lactation follow a separate pathway with specific data and safeguards.
1. Resting metabolism
Standard mode uses Mifflin-St Jeor. Male: 10 × weight kg + 6.25 × height cm − 5 × age + 5. Female: the same formula with −161 instead of +5.
2. Total expenditure
Resting metabolism is multiplied by 1.2 for sedentary, 1.55 for moderately active or 1.725 for active. The result estimates TDEE, total daily energy expenditure.
3. Goal
Maintenance uses TDEE. For weight loss or gain, the software translates weekly pace into an initial imbalance and applies internal limits. The result remains an estimate that should be reviewed over time.
4. Macronutrients
The profile percentages are applied to energy: protein and carbohydrate provide 4 kcal/g and fat 9 kcal/g, using the factors in EU Regulation 1169/2011.
Precise mode
A plausible lean-mass value changes the equation.
When the user selects precise mode and supplies a plausible body-fat percentage, NUTRIMI calculates lean mass and uses 370 + 21.6 × lean mass in kg. If no usable measure exists, the software falls back to Mifflin-St Jeor instead of inventing data. The 370 + 21.6 × lean-mass equation was proposed by Cunningham in 1991 and is often labelled Katch-McArdle in calculators.
Circumferences
Without a direct value, the software can estimate it from height, neck, waist and, where required, hips; missing data or implausible results trigger a fallback.
Pregnancy excluded
Waist is not suitable for this estimate during pregnancy, so precise mode is disabled and the dedicated maternal pathway is used.
The 7,700 kcal/kg imbalance is not a forecast of future weight.
The code uses 7,700 kcal per kilogram only to translate a requested weekly pace into an initial deficit or surplus. NIH research shows that body-weight response is dynamic and that the static rule often overpredicts long-term weight loss. Trend, adherence, body composition and clinical status therefore need reassessment.
Frequently asked questions
What the result actually means.
How is a daily calorie requirement calculated?
Resting metabolism is estimated with Mifflin-St Jeor or, when plausible lean mass is available, with 370 + 21.6 per kilogram of lean mass. The result is then multiplied by activity level.
Does artificial intelligence decide how many calories to eat?
No. The target uses deterministic formulas and profile data. AI can help interpret a meal, but the output is editable and does not autonomously change the requirement.
How are macro grams calculated?
After applying the profile percentages, energy assigned to protein and carbohydrate is divided by 4 kcal/g, while energy assigned to fat is divided by 9 kcal/g.
Is the result a prescription?
No. It is a software estimate. Medical conditions, pregnancy, lactation, therapy, eating disorders, competitive sport and clinical goals require professional assessment.
Main references
Original and institutional sources.
PubMed