The Macronutrient Calculator estimates basal metabolic rate, total daily energy expenditure, target calories, and daily protein, carbohydrate, and fat grams from sex, age, weight, height, activity, goal, and macro split.
Calculation method
It uses Mifflin-St Jeor for BMR, multiplies by an activity factor, adjusts target calories by 500 for loss or gain, applies a sex-specific minimum, then converts macro calories using 4 kcal/g for protein and carbohydrates and 9 kcal/g for fat.
Example
For a 30-year-old, 70 kg, 175 cm male with moderate activity and a maintenance goal, the calculator first estimates BMR, multiplies by 1.55 for TDEE, and divides target calories using the selected split.
Questions
Are the calorie targets medical advice?
No. They are estimates based on population equations and selected assumptions.
Why do macro grams not add back exactly to calories?
Rounding each gram value can create a small displayed difference.
Can I use this during pregnancy?
Do not use generic calorie targets for pregnancy or a medical condition without clinician guidance.
Health notice and limitations
The calculator does not model body composition, metabolic adaptation, medication, pregnancy, breastfeeding, or individual clinical needs.