Macronutrient Calculator

The number of calories your body burns at rest, just to maintain basic functions like breathing, circulation, and cell production. Calculated using the Mifflin–St Jeor formula (or Katch–McArdle if you provide body fat %).

Your BMR multiplied by your activity level. This is the total calories you burn in a day with your current exercise habits. Your calorie target is based on TDEE adjusted for your goal (burn fat, build muscle, maintain, etc.).

• Protein: 4 calories per gram — Essential for muscle repair and growth.
• Carbs: 4 calories per gram — Primary fuel source for energy and workouts.
• Fat: 9 calories per gram — Critical for hormone production and nutrient absorption.

1. Protein is set first: Based on your target weight × protein per lb (1.0–1.5g/lb).
2. Calculate protein calories: Protein grams × 4 = protein calories.
3. Remaining calories: Total calories − protein calories.
4. Carbs & Fat split proportionally: Both decrease or increase together based on the remaining calories. Carbs get ~67%, Fat gets ~33% of what's left (based on standard ratios of 1.1g/lb carbs and 0.5g/lb fat).
5. Total calories verified: Protein calories + Carb calories + Fat calories = Your daily target.

• Calculated: TDEE × your goal multiplier (e.g., build muscle = TDEE × 1.10).
• Target Weight: TDEE × goal multiplier, anchors all macros to your goal weight.
• Target Body Fat %: TDEE × goal multiplier, estimates weight at target BF%, anchors macros there.
• Manual Calories: You set the exact calorie target; macros adjust accordingly.

When you increase protein (1.0 → 1.2 → 1.5 g/lb), protein calories increase. Carbs and fat both decrease proportionally to keep your total calorie target consistent. This ensures higher protein intake without exceeding your daily calorie goal.