Macro calculator: protein, carbs and fat
Enter your details to get daily calories and a macro split in grams. The calculation uses the Mifflin-St Jeor equation, the same one used inside the My Meal AI app.
How the macro calculation works
- 1. Basal metabolic rate. 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 (male) or − 161 (female).
- 2. Daily needs (TDEE). Multiply by an activity factor from 1.2 to 1.9.
- 3. Goal adjustment. −20% to lose fat, +12% to gain muscle.
- 4. Macro split. Protein 1.6-2.2 g/kg, fat 0.8-1 g/kg, carbs fill the rest (protein and carbs = 4 kcal/g, fat = 9 kcal/g).
Knowing your macros is easy. Tracking them isn't.
My Meal AI reads a photo of your plate, estimates the macros of the meal and compares your day against these targets.
Try it freeFAQ
Which macro matters most?
Protein. It preserves muscle in a deficit and keeps you full. Hit it first, then adjust carbs and fat to your preference.
How often should I recalculate?
Every 4-6 kg of body weight change, or whenever your training volume changes for good.
Can I track macros without weighing food?
Yes. A photo-based estimate is accurate enough to follow a weekly trend.
Sources and method
Energy uses the Mifflin-St Jeor equation. Protein ranges follow sports-nutrition guidance for active adults. References: Mifflin et al. and JISSN protein position stand.
These results are informational estimates and do not replace personalised medical advice.
Estimates only. Not medical advice. Service reserved for people aged 18 and over.
Published and reviewed by the My Meal AI team. Last updated: September 18, 2026.