Macro Calculator

Macronutrients are the three main categories of nutrients your body uses for energy: carbohydrates, protein, and fat. Carbs provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram. Tracking macros goes beyond just counting calories — it helps ensure your body gets the right fuel for your specific goals.

This calculator uses the Mifflin St Jeor equation to estimate your Basal Metabolic Rate (BMR) — the calories your body burns at rest. BMR is then multiplied by an activity factor based on your lifestyle to get your Total Daily Energy Expenditure (TDEE). Your goal adjustment (weight loss or gain) is applied on top of that to set your final calorie target.

For weight loss, a common approach is a higher protein intake (30–35% of calories) to preserve muscle, moderate fat (25–35%), and lower carbs. A calorie deficit of 500 calories/day (~1 lb/week loss) is generally sustainable. Choosing the Low Carb / High Fat preference in this calculator will adjust the split accordingly.

The 40-40-20 rule is a popular macro split where 40% of your calories come from carbohydrates, 40% from protein, and 20% from fat. It is commonly used by athletes and bodybuilders aiming to build muscle while keeping fat intake controlled. This calculator's 'Moderate Carb / Moderate Fat' setting approximates a balanced split similar to this approach.

The easiest way is to check nutrition labels, which list grams of carbs, protein, and fat per serving. For whole foods without labels, apps like MyFitnessPal or Cronometer have large databases. Once you know your daily gram targets from this calculator, you can log meals and adjust portions until your daily totals match your goals.

Tracking macros can be very effective if you have a specific physique or performance goal — such as losing fat, building muscle, or improving athletic endurance. It provides more precision than just counting calories. That said, it requires consistency and may not suit everyone. Even tracking loosely for a few weeks can improve your awareness of what you eat.

For muscle gain, you need a calorie surplus — typically 250–500 calories above your TDEE. Protein intake should be high (around 0.7–1 g per pound of body weight) to support muscle protein synthesis. Select the 'Weight Gain' goal in this calculator and use the 'High Carb / Low Fat' or 'Moderate' macro preference to generate a bulking macro plan.

Yes. As your weight changes, your BMR and TDEE shift, which means your calorie and macro targets should be recalculated periodically. A good rule of thumb is to recalculate every 4–6 weeks, or whenever your weight changes by 5 or more pounds, to keep your targets accurate and your progress on track.