Macronutrient Breakdown Calculator

About the Macronutrient Calculator

This Macronutrient Calculator is designed to help you optimize your nutrition based on your personal fitness goals — whether you want to lose fat, maintain weight, or build muscle.

It starts by calculating your Total Daily Energy Expenditure (TDEE) using your age, gender, height, weight, and activity level. Then, based on your goal, it distributes your calories into the three key macronutrients: protein, carbohydrates, and fats.

Here’s how it works:

• First, we estimate your Basal Metabolic Rate (BMR) using the Revised Harris–Benedict Equation — a scientifically recognized formula for resting calorie needs.
• Next, we apply an activity multiplier to account for your daily lifestyle and workouts, giving us your TDEE.
• Finally, we break down your calories into macros based on the split you select — Balanced, High-Protein, Low-Carb, Keto, or a Custom plan.

Each macro split is tailored to support specific outcomes. For example, a higher-protein ratio can help preserve muscle during a fat-loss phase, while a low-carb approach may better suit those aiming for ketosis.

Scientific Reference:
Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO.
A new predictive equation for resting energy expenditure in healthy individuals.
American Journal of Clinical Nutrition, 1990; 51(2):241–247.
doi:10.1093/ajcn/51.2.241

Whether you're fine-tuning your performance, targeting fat loss, or building muscle mass, this calculator gives you a science-backed plan to fuel your success with confidence.