Macronutrients — protein, carbohydrates, and fat — are the three categories of calories your body uses for fuel. Getting your total calories right matters. Getting your macro split right matters more if you have specific body composition goals.
Step 1: Calculate Your TDEE
TDEE (Total Daily Energy Expenditure) is how many calories you burn in a day, including activity. It's the foundation of any macro plan. Your calorie target is then set above or below your TDEE depending on your goal: weight loss, maintenance, or muscle building.
Protein: The Most Important Macro
Protein has 4 calories per gram. It's the most satiating macro and the most critical for preserving or building muscle. Standard recommendations: 0.7–1.0 grams per pound of body weight (1.6–2.2 g/kg) for those strength training. More sedentary individuals can get by with 0.5–0.7 g/lb.
For a 180 lb person doing regular strength training: 126–180 grams of protein per day. At 4 calories/gram, that's 504–720 protein calories — roughly 25–35% of a 2,000-calorie diet.
Common Macro Splits by Goal
- •Weight loss: 30–35% protein / 30–40% carbs / 25–35% fat
- •Muscle building: 25–30% protein / 45–55% carbs / 20–30% fat
- •Athletic performance: 20–25% protein / 50–60% carbs / 20–25% fat
- •Low-carb/keto: 20–30% protein / 5–10% carbs / 60–75% fat
- •Maintenance: 20–25% protein / 45–55% carbs / 25–35% fat
Protein and carbs each have 4 calories per gram. Fat has 9 calories per gram. This means a "30% fat" diet on 2,000 calories equals 600 fat calories ÷ 9 = 67 grams of fat — not 30% of grams.
For most people, tracking protein is the highest-leverage move. Get your protein target right first, then fill the remaining calories with carbs and fat in whatever ratio feels sustainable. Dietary adherence matters more than the perfect macro split on paper.
Frequently Asked Questions
What are macros?
Macros (macronutrients) are the three main categories of nutrients that provide calories: protein (4 cal/g), carbohydrates (4 cal/g), and fat (9 cal/g). Tracking macros means hitting specific gram targets for each rather than just counting total calories — giving you control over body composition, not just weight.
Calculate your macros →How much protein should I eat per day?
For general health: 0.8g per kg of body weight (RDA). For muscle building or fat loss while preserving muscle: 1.6–2.2g per kg (0.7–1.0g per lb). A 170 lb person in a strength program should aim for 119–170g of protein per day. Spreading protein across 4+ meals maximizes muscle protein synthesis.
Get your personalized macro breakdown →What macro ratio is best for weight loss?
High protein (30–40% of calories) + moderate fat (30–35%) + lower carbs (25–35%) is the most research-supported ratio for weight loss, as protein reduces hunger and preserves muscle mass during a deficit. Exact ratios matter less than total calorie deficit and adequate protein. Start with 40/30/30 (protein/fat/carbs) if unsure.
Do macros matter more than total calories?
Total calories are the primary driver of weight change — a calorie deficit causes weight loss regardless of macro split. But macros determine body composition: adequate protein preserves muscle while losing fat; very low protein causes more muscle loss. For physique goals (not just scale weight), both calories and protein intake matter critically.
What's the best macro split for building muscle?
For muscle gain (lean bulk), aim for: Protein 25–30%, Carbs 45–55%, Fat 20–30%. Carbohydrates fuel workouts and aid recovery; protein provides building blocks; fat supports hormone production. The key is being in a small calorie surplus (200–300 cal above TDEE) with 1.6–2.2g protein/kg/day.
Find your calorie surplus target →