How the macro calculator works
The maths is the same approach used by sports dietitians:
- BMR — Mifflin-St Jeor:
10×kg + 6.25×cm − 5×age + 5 (male) or − 161 (female) - TDEE — BMR × activity multiplier (1.2 sedentary → 1.9 athlete)
- Goal adjustment — fat loss subtracts 20%, lean gain adds 10%, maintenance keeps it flat
- Macros — 30% protein, 40% carbs, 30% fat by calories (4 kcal/g protein and carbs, 9 kcal/g fat)
Choosing the right activity level
Most people pick a level too high. A useful rule of thumb: "moderately active" means you exercise hard three to five times a week and you walk a fair amount in daily life. If you sit most of the day and lift three times a week, you're more like "lightly active".
Protein matters more than the split
If you remember one number, remember protein. Hitting 1.6–2.2 g/kg keeps you full, protects muscle in a deficit and supports gains in a surplus. The carb/fat split below protein is more about personal preference and performance than physique.
Adjusting over time
Track weight as a 7-day average. If fat loss stalls for two weeks, drop calories by ~100 or add 1,000 daily steps. If you're not gaining on a surplus, add 100–150 calories. Don't overhaul macros every few days.
Try it with our other tools
Pair these macros with our BMI calculator for a quick status check, or our Chipotle calorie calculator if takeout is part of your week.