How to Calculate Your Macros: A Step-by-Step Guide

Macronutrients (protein, carbohydrates, and fats) are the building blocks of your diet. Calculating the right balance for your goals can help support muscle growth, fat loss, or maintenance. This guide complements our macro calculator, walking you through the science and the steps.

Step 1: Determine Your Calorie Target

Before splitting macros, you need a total calorie target. Estimate your Total Daily Energy Expenditure (TDEE) using our TDEE calculator. For fat loss, aim for 300–500 calories below TDEE. For muscle gain, aim for 200–400 above. For maintenance, match TDEE.

Protein: The Priority Macro

Protein supports muscle protein synthesis, satiety, and thermogenesis. Schoenfeld & Aragon (2018) found in their meta-analysis that 1.6–2.2 g per kg of body weight may optimize muscle gains for individuals engaged in resistance training. The International Society of Sports Nutrition (ISSN) position stand aligns with these recommendations.

Set protein first. For an 80 kg lifter: 1.6 × 80 = 128 g minimum; 2.2 × 80 = 176 g for the upper end. Use our protein calculator for goal-specific targets.

Fat: Set a Floor, Not a Ceiling

Dietary fat supports hormone production, cell function, and absorption of fat-soluble vitamins. ISSN recommends a minimum of 0.4 g per kg of body weight to support hormonal health. Many individuals function well with 0.5–1.0 g/kg.

For an 80 kg person: 0.4 × 80 = 32 g minimum. Fat provides 9 calories per gram, so 32 g = 288 calories from fat.

Carbohydrates: Fill the Rest

Carbs fuel training and replenish glycogen. After setting protein and fat, allocate remaining calories to carbohydrates. Carbs provide 4 calories per gram.

Example: 2,000 cal target, 160 g protein (640 cal), 65 g fat (585 cal). Remaining: 2,000 − 640 − 585 = 775 cal ÷ 4 = ~194 g carbs.

Goal-Specific Splits

Fat Loss

Prioritize protein (upper end of 1.6–2.2 g/kg) to preserve muscle. Keep fat at the floor. Fill remaining calories with carbs; lower carbs may help some people with adherence.

Muscle Gain

Protein at 1.6–2.2 g/kg. Higher carbs may support performance and recovery. Fat can remain at 0.5–1.0 g/kg.

Maintenance

Same protein targets. Carb and fat distribution is flexible based on preference, training schedule, and how you feel.

Putting It Together

Use our macro calculator to get numbers quickly. Track for 2–3 weeks and adjust based on weight change, performance, and recovery. Individual needs vary; these are starting points, not rules.