How to Calculate Your Macros for Weight Loss, Muscle Gain or Maintenance

Blog › Health · 9 min read · Published 2026-05-06

What macros are, how to set protein, carb, and fat targets, and ratios for cutting, bulking, and recomposition.

What Are Macros?

Macronutrients — protein, carbohydrate, and fat — are the three nutrients that supply calories. Counting macros means tracking how many grams of each you eat, not just total calories. Two diets with the same calorie count can produce wildly different results in body composition, hunger, and performance based purely on the macro split.

Why Macros Matter Beyond Calories

Calories drive weight change; macros drive what kind of weight you change. A 2,000-calorie diet with 50 g of protein will lose more muscle than the same 2,000 calories with 150 g of protein. A high-fat keto diet and a high-carb diet at the same calories will feel very different in energy, performance, and hunger — even though the scale moves the same.

Step 1 — Find Your Calorie Target

Start with TDEE. The TDEE Calculator gives you maintenance. From there:

Cutting (fat loss): 15–25% below TDEE
Maintenance: ±5% of TDEE
Lean bulk: 10–20% above TDEE

Step 2 — Set Protein

Protein is the priority macro. Targets in grams per kilogram of body weight:

Sedentary adult: 0.8–1.0 g/kg
Active adult: 1.2–1.6 g/kg
Strength training, maintenance: 1.6–2.0 g/kg
Strength training, cutting: 2.0–2.4 g/kg
Strength training, lean bulk: 1.6–2.0 g/kg

Each gram of protein supplies 4 calories. A 75 kg lifter cutting at 2.2 g/kg eats 165 g of protein → 660 cal from protein.

Step 3 — Set Fat

Fat supports hormones and absorbs vitamins. The minimum useful intake is 0.6 g per kg of body weight; many do best at 0.8–1.0 g/kg. Each gram of fat supplies 9 calories. For our 75 kg lifter, 0.8 g/kg = 60 g fat → 540 cal.

Step 4 — Carbs Fill the Rest

Subtract protein and fat calories from your total, then divide the remainder by 4 (calories per gram of carb). For the example above:

Cut target: 2,000 cal
Protein: 660 cal
Fat: 540 cal
Remaining: 2,000 − 660 − 540 = 800 cal → 200 g carbs

Run the same logic instantly with the Macro Calculator.

Cutting vs Bulking Ratios

A useful rule of thumb for trained lifters:

Aggressive cut: 40% protein / 30% fat / 30% carb
Moderate cut: 35P / 25F / 40C
Maintenance: 30P / 25F / 45C
Lean bulk: 25P / 25F / 50C
Endurance training: 20P / 25F / 55C

Tracking Macros — What Works

Weigh foods raw on a kitchen scale — package estimates are wrong by 10–20%
Log everything for 14 days — long enough to spot patterns, short enough to stick with
Use a barcode-scan app — MyFitnessPal, MacroFactor, Cronometer
Front-load protein in early meals — appetite drops by mid-day, hardest macro to hit late
Round consistently — perfectionism kills adherence; ±5 g per macro is fine

Common Macro Mistakes

Setting protein too low and losing muscle during a cut
Over-restricting fat below 0.6 g/kg, harming hormones and satiety
Ignoring fibre — aim for 25–35 g/day for satiety and gut health
Treating "if it fits your macros" as a free pass to eat junk — micronutrients still matter
Re-using the same numbers after losing 5+ kg without recalculating

How Long to Stay on a Cut or Bulk

Cuts typically run 8–16 weeks; longer cuts compound metabolic adaptation. Bulks run 12–24 weeks before adipose gain outpaces lean gain. Use the Calorie Deficit Calculator to time fat-loss phases.