Free Macro Calculator

What Are Macros?

Macronutrients (or "macros") are the three main nutrients that provide calories and energy: protein, carbohydrates, and fats. Each plays a unique role in your body's functioning and achieving your fitness goals.

Unlike micronutrients (vitamins and minerals) which are needed in small amounts, macronutrients are required in large quantities and make up the bulk of your daily calorie intake.

The Three Macronutrients

Protein (4 calories per gram)

Protein is essential for building and repairing muscle tissue, producing enzymes and hormones, and supporting immune function. For fitness goals, protein is particularly important because it:

• Preserves muscle during fat loss — Higher protein intake helps maintain lean mass when in a calorie deficit
• Supports muscle growth — Provides amino acids needed to build new muscle tissue
• Increases satiety — Protein is the most filling macronutrient, helping control hunger
• Has a high thermic effect — Your body burns 20-30% of protein calories during digestion

Carbohydrates (4 calories per gram)

Carbohydrates are your body's preferred energy source, especially for high-intensity exercise. They fuel your workouts, support brain function, and help with recovery. Benefits include:

• Primary fuel for intense training — Carbs power anaerobic exercise and weightlifting
• Glycogen replenishment — Restores muscle energy stores after workouts
• Supports anabolic hormones — Adequate carbs help maintain testosterone and thyroid function
• Fiber for digestive health — Complex carbs provide essential fiber

Fats (9 calories per gram)

Dietary fats are essential for hormone production, nutrient absorption, and cell membrane health. Despite having more calories per gram, fats are crucial for optimal health:

• Hormone production — Essential for testosterone, estrogen, and other hormones
• Vitamin absorption — Vitamins A, D, E, and K require fat for absorption
• Satiety — Fats slow digestion and help you feel full longer
• Brain and nerve function — Your brain is about 60% fat

How Macros Are Calculated

Step 1: Calculate Your TDEE

Total Daily Energy Expenditure (TDEE) is the total number of calories you burn each day. This calculator uses the Mifflin-St Jeor equation for BMR, then applies an activity multiplier:

Step 2: Adjust for Your Goal

Goal	Calorie Adjustment	Expected Result
Fat Loss	15-25% deficit	0.5-1.5 lbs/week loss
Maintenance	No change	Weight stability
Muscle Gain	200-500 surplus	0.5-1 lb/week gain

Step 3: Set Protein

Protein is set first based on bodyweight and goals:

Situation	Protein Target
No resistance training, maintenance	0.8g per lb bodyweight
Resistance training OR fat loss	1.0g per lb bodyweight
Advanced lifter in deficit	1.0-1.2g per lb bodyweight

Step 4: Split Remaining Calories

After protein is set, remaining calories are divided between carbs and fats based on your preference. Neither split is inherently better for fat loss—the best approach is the one you can stick to.

Macro Ratios by Goal

Fat Loss

When losing fat, protein becomes even more important to preserve muscle mass. A typical fat loss macro split might look like:

High Carb: 40% protein, 40% carbs, 20% fats
Low Carb: 40% protein, 25% carbs, 35% fats

Muscle Building

Building muscle requires a calorie surplus and adequate protein. Carbs become more important to fuel workouts:

Typical: 25% protein, 50% carbs, 25% fats

Maintenance

Maintenance is more flexible. Focus on hitting protein targets and fill in carbs/fats based on preference:

Balanced: 25-30% protein, 40-45% carbs, 25-30% fats

Tips for Hitting Your Macros

• Track your food — Use an app like MyFitnessPal or Cronometer to log meals
• Weigh your portions — Eyeballing is notoriously inaccurate; a food scale is essential
• Plan meals ahead — Pre-logging makes hitting targets much easier
• Prioritize protein — Eat protein at every meal to hit your target more easily
• Be flexible with carbs/fats — If you're under on carbs but over on fats (or vice versa), it's not a big deal
• Focus on consistency — Being close most days matters more than being perfect occasionally

Common Mistakes to Avoid

• Not counting cooking oils, sauces, and condiments
• Underestimating portion sizes
• Overestimating activity level
• Eating back all exercise calories
• Obsessing over hitting exact numbers instead of ranges
• Not adjusting when progress stalls

When to Recalculate

Your macro needs change as your body and goals change. Recalculate when: