How to Calculate Your Macros for Weight Loss or Muscle Gain

You have heard it a hundred times: "track your macros." But nobody explains how to actually calculate them. The fitness influencers make it sound like you need a PhD in nutrition to figure out how many grams of protein to eat. You do not. The math is straightforward once you know the formulas, and the research has converged on clear targets that work for almost everyone.

What Are Macros and Why Do They Matter?

Macronutrients are the three calorie-providing nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each serves a different function:

• Protein (4 calories per gram): Builds and repairs muscle tissue, supports immune function, and has the highest thermic effect of food (your body burns more calories digesting protein than carbs or fat).
• Carbohydrates (4 calories per gram): Primary fuel for high-intensity exercise and brain function. Stored as glycogen in muscles and liver.
• Fat (9 calories per gram): Essential for hormone production, vitamin absorption, and cell membrane integrity.

Total daily energy intake sets the ceiling for body composition change. But the ratio of protein, carbs, and fat determines what changes. In a calorie deficit, adequate protein preserves muscle. In a surplus, adequate protein and carbs drive muscle growth while minimizing fat gain.

Step 1: Calculate Your TDEE

Total Daily Energy Expenditure (TDEE) is the number of calories you burn per day. It is the sum of your basal metabolic rate (BMR), the thermic effect of food, non-exercise activity, and exercise energy expenditure.

The most accurate field method uses the Mifflin-St Jeor equation for BMR, multiplied by an activity factor:

For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5

For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161

Then multiply by your activity level:

Activity Level	Multiplier	Description
Sedentary	1.2	Desk job, minimal exercise
Lightly active	1.375	Light exercise 1 to 3 days per week
Moderately active	1.55	Moderate exercise 3 to 5 days per week
Very active	1.725	Hard exercise 6 to 7 days per week
Extremely active	1.9	Physical job plus hard training daily

Our TDEE Calculator does this math for you. You can also use our BMR Calculator if you want just the basal number.

Step 2: Set Your Calorie Target

Your goal determines whether you eat above or below TDEE:

Cutting (fat loss): 10% to 25% below TDEE. A moderate deficit of 15% (300 to 500 calories below maintenance) preserves the most lean mass. Target 0.5% to 0.7% body weight loss per week.

Bulking (muscle gain): 5% to 15% above TDEE. Target 0.25% to 0.5% body weight gain per week. A surplus larger than 500 calories per day primarily adds fat without accelerating muscle growth.

Recomposition (simultaneous fat loss and muscle gain): Maintenance plus or minus 100 to 200 calories. Realistic mainly for beginners, returning trainees, and those with higher body fat percentages. A 2026 study published in the European Journal of Applied Physiology found that participants consuming 2.5 g/kg/day of protein at maintenance calories achieved meaningful body recomposition over 12 weeks.

Step 3: Calculate Your Protein Target

Protein is set first because its target is the most precisely defined by research.

For bulking, a landmark 2018 meta-analysis by Morton et al. in the British Journal of Sports Medicine analyzed 49 studies and 1,863 participants. It found that protein intake above 1.62 g/kg/day produced no additional gains in fat-free mass from resistance training. The practical range:

• Bulking: 1.6 to 2.2 g/kg of total body weight per day

For cutting, protein requirements rise to protect lean mass. Helms et al. (2014) in the Journal of the International Society of Sports Nutrition recommends:

• Cutting: 2.3 to 3.1 g/kg of lean body mass per day

The Longland et al. 2016 RCT in the American Journal of Clinical Nutrition demonstrated this in practice: 40 men in a 40% calorie deficit with resistance training gained lean mass on 2.4 g/kg/day protein but lost it on 1.2 g/kg/day. Same training, same deficit, very different outcomes.

If you have higher body fat (25% or more), calculate protein based on lean body mass rather than total weight. Our Lean Body Mass Calculator can give you that number.

Step 4: Calculate Your Fat Target

Dietary fat is essential for hormone production. Dropping below 20% of daily calories from fat can reduce testosterone in men, as documented by multiple studies including a 1997 review by Volek et al.

• Minimum fat floor: 0.6 to 0.8 g/kg of body weight per day
• Cutting: 0.8 to 1.0 g/kg (lower end to leave room for carbs)
• Bulking: 0.8 to 1.2 g/kg

Step 5: Fill the Rest with Carbohydrates

After setting protein and fat, the remaining calories come from carbohydrates. Carbs fuel training performance and glycogen replenishment.

Carbs (in grams) = (Total Calories - Protein Calories - Fat Calories) / 4

Here is a summary of typical macro splits by goal:

Phase	Protein	Fat	Carbs	Typical % Split
Aggressive cut (25% deficit)	2.8 to 3.1 g/kg LBM	0.8 g/kg BW	Remainder	40/30/30
Moderate cut (15% deficit)	2.3 to 2.6 g/kg LBM	1.0 g/kg BW	Remainder	35/25/40
Maintenance / recomp	1.8 to 2.2 g/kg BW	1.0 g/kg BW	Remainder	30/25/45
Lean bulk (10% surplus)	1.6 to 2.0 g/kg BW	1.0 to 1.2 g/kg BW	Remainder	25/22/53

Our Macro Calculator handles all five steps automatically and gives you precise gram targets based on your stats and goal.

Real-World Scenarios

Alex: The 25-Year-Old Cutting for Summer

Alex is 25, 5'11", 185 lbs (84 kg), moderately active (trains 4 days per week). He wants to cut from 18% body fat to 12%.

1. BMR: (10 x 84) + (6.25 x 180) - (5 x 25) + 5 = 1,793 kcal
2. TDEE: 1,793 x 1.55 = 2,779 kcal
3. Cut target (15% deficit): 2,779 x 0.85 = 2,362 kcal
4. Protein (2.4 g/kg LBM): LBM = 84 x (1 - 0.18) = 68.9 kg. Protein = 2.4 x 68.9 = 165 g (660 kcal)
5. Fat (0.9 g/kg BW): 0.9 x 84 = 76 g (684 kcal)
6. Carbs: (2,362 - 660 - 684) / 4 = 254 g (1,018 kcal)

Alex's daily macros: 165g protein, 76g fat, 254g carbs, 2,362 total calories.

Jessica: The 30-Year-Old Lean Bulking

Jessica is 30, 5'6", 140 lbs (63.5 kg), very active (trains 5 days per week). She wants to build muscle without adding excess fat.

1. BMR: (10 x 63.5) + (6.25 x 168) - (5 x 30) - 161 = 1,359 kcal
2. TDEE: 1,359 x 1.725 = 2,344 kcal
3. Bulk target (10% surplus): 2,344 x 1.10 = 2,578 kcal
4. Protein (1.8 g/kg BW): 1.8 x 63.5 = 114 g (456 kcal)
5. Fat (1.0 g/kg BW): 1.0 x 63.5 = 64 g (576 kcal)
6. Carbs: (2,578 - 456 - 576) / 4 = 387 g (1,546 kcal)

Jessica's daily macros: 114g protein, 64g fat, 387g carbs, 2,578 total calories.

She should also track her calorie intake using our Calorie Calculator to make sure she is hitting her target consistently.

Common Mistakes

1. Setting protein too low during a cut. This is the number one mistake. Under-eating protein in a calorie deficit means you lose muscle along with fat. The 2026 European Journal of Applied Physiology study confirmed that 2.5 g/kg/day preserves lean mass even in a modest deficit.

2. Cutting fats too aggressively. Dropping fat below 0.6 g/kg can suppress testosterone and other hormones. Fat is not the enemy, even when cutting.

3. Using total body weight for protein when body fat is high. If you are 30% body fat, calculating protein based on total weight overestimates your needs. Use lean body mass instead.

4. Changing macros too frequently. Stick with your targets for at least 2 to 3 weeks before adjusting. Body weight fluctuates daily due to water, glycogen, and digestion. Trends matter, not single days.

External Research and Resources

• Morton et al. 2018 Meta-Analysis (British Journal of Sports Medicine) analyzed 49 studies and found that protein intake above 1.62 g/kg/day produced no additional lean mass gains from resistance training.
• Helms et al. 2014 (Journal of the International Society of Sports Nutrition) established the 2.3 to 3.1 g/kg LBM protein recommendation for cutting phases in resistance-trained individuals.
• Longland et al. 2016 (American Journal of Clinical Nutrition) demonstrated that high protein (2.4 g/kg/day) in a 40% deficit preserved and built lean mass while low protein (1.2 g/kg/day) did not.

People Also Ask

How many macros should I eat to lose weight?

Start with a 15% calorie deficit below TDEE. Set protein at 2.3 to 3.1 g/kg of lean body mass, fat at 0.8 to 1.0 g/kg of body weight, and fill the rest with carbs. This preserves muscle while burning fat.

How much protein do I need to build muscle?

The research converges on 1.6 to 2.2 g/kg of body weight per day for muscle gain. A 2018 meta-analysis found no additional benefit above 1.62 g/kg/day. More is not better once you cross that threshold.

Should I track macros or just calories?

Track both. Calories determine whether you gain or lose weight. Macros determine whether that weight is muscle or fat. Tracking macros ensures you get enough protein to build or preserve muscle and enough fat for hormone health.

How long does it take to see results from macro tracking?

Expect visible changes after 4 to 8 weeks of consistent tracking. Body weight may shift within 1 to 2 weeks due to water and glycogen changes, but meaningful body composition change takes at least a month to become visible.

Related Calculators

• Macro Calculator - Calculate your macronutrient needs
• TDEE Calculator - Calculate total daily energy expenditure
• BMR Calculator - Calculate your basal metabolic rate
• Calorie Calculator - Calculate daily calorie needs
• Protein Calculator - Calculate protein requirements
• Carbohydrate Calculator - Calculate daily carb requirements
• Fat Intake Calculator - Calculate daily fat intake