Macronutrient Calculator

What Are Macronutrients?

Macronutrients — protein, carbohydrates, and fat — are the three nutrients your body needs in large amounts, and the only ones that provide calories. "Counting macros" means tracking how many grams of each you eat daily, rather than just total calories, to support a specific goal like building muscle or maintaining energy.

Calories Per Gram

This calculator first estimates your daily calorie needs using the Mifflin-St Jeor equation and your activity level, then divides those calories into grams of each macro based on your chosen split.

How Your Calorie Target Is Calculated

The Mifflin-St Jeor equation estimates your Basal Metabolic Rate (the calories you burn at rest), which is then multiplied by an activity factor to get your total daily energy expenditure (TDEE). Your goal then adjusts this: a modest reduction for weight loss, maintenance calories to stay the same, or a modest surplus to support muscle building.

How to Use This Calculator

Enter your age, weight, height, and biological sex, then pick your activity level honestly — most people overestimate it. Choose your goal and a macro split style. The result shows grams, calories, and percentages for each macronutrient, plus a rough per-meal breakdown.

Choosing a Macro Split

• Balanced (30/40/30): a sensible default for general health and most activity levels
• High Protein (40/35/25): popular for muscle building and preserving lean mass
• Low Carb (35/25/40): favored by some for appetite control and steady energy
• Endurance (25/55/20): higher carbs to fuel long-duration training

Why Protein Gets Special Attention

Among the three macros, protein is the one most research consistently emphasizes — for preserving muscle mass, supporting recovery from exercise, and keeping you feeling full. A common general guideline is roughly 1.6–2.2 grams of protein per kilogram of body weight for active individuals, though your needs vary with age, training, and goals.

Important Health Note

This tool provides general nutritional estimates for informational purposes only — it is not a personalized meal plan, diet prescription, or medical advice. Calorie and macro needs vary significantly between individuals based on factors this calculator can't assess. If you have a health condition, are pregnant, have a history of disordered eating, or are making significant dietary changes, please consult a registered dietitian or your doctor first.

Where This Fits Your Routine

Pair your macro targets with our TDEE calculator to understand your energy expenditure, our BMI calculator for a general body composition snapshot, and our water intake calculator to round out your daily targets.

Frequently Asked Questions