How to Calculate Your Macros for Weight Loss

If you've heard people talk about "hitting their macros," you might be wondering what it actually means — and more importantly, how to calculate the right numbers for your body and goals.

This guide breaks it all down: what macros are, why they matter for weight loss, and how to calculate them step-by-step.

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What are macros — visual breakdown of protein, carbs and fat with calorie counts

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Clean flat-design infographic on a white background. Three columns: 'Protein 4 cal/g' (green icon of chicken breast), 'Carbohydrates 4 cal/g' (blue icon of bread/rice), 'Fat 9 cal/g' (orange icon of avocado). Title at top: 'The 3 Macronutrients'. Minimalist modern fitness brand style. No photography.

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What Are Macros?

"Macros" is short for macronutrients — the three main nutrients your body needs in large amounts:

• Protein — 4 calories per gram. Builds and repairs muscle, keeps you full, and preserves lean mass during weight loss.
• Carbohydrates — 4 calories per gram. Your body's primary energy source, especially for exercise.
• Fat — 9 calories per gram. Essential for hormone production, brain function, and absorbing fat-soluble vitamins.

Every food you eat contains some combination of these three macronutrients. Understanding how much of each you need gives you far more control over your body composition than simply counting calories alone.

Why Macros Matter More Than Just Calories

Two people can eat 1,800 calories a day and get completely different results.

Person A eats mostly carbs and fat, with very little protein. They'll lose weight, but much of it will be muscle — leaving them lighter but softer.

Person B hits a high-protein target while managing carbs and fat. They preserve muscle and lose primarily body fat — ending up leaner and stronger at the same weight.

Same calories. Completely different outcomes. That's the power of tracking macros.

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Side-by-side body composition comparison: calorie deficit only vs. calorie deficit + high protein

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Split comparison chart (two columns). Left: 'Calories Only' — body silhouette losing both fat and muscle (shown in grey). Right: 'Macros + High Protein' — body silhouette losing mostly fat (orange), preserving muscle (green). Clean flat design, white background, branded with MyMacroFit green (#22c55e). Label: 'Same Deficit. Different Results.' Modern fitness infographic style.

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How to Calculate Your Macros in 4 Steps

Step 1: Calculate Your BMR

Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest. We use the Mifflin-St Jeor equation — the most accurate formula for most people:

Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

Step 2: Find Your TDEE

Your Total Daily Energy Expenditure (TDEE) accounts for your activity level:

| Activity Level | Multiplier | |---|---| | Sedentary (desk job, no exercise) | BMR × 1.2 | | Lightly active (1–3 days/week) | BMR × 1.375 | | Moderately active (3–5 days/week) | BMR × 1.55 | | Very active (6–7 days/week) | BMR × 1.725 | | Extra active (physical job + exercise) | BMR × 1.9 |

Step 3: Apply a Calorie Deficit

For weight loss, subtract 500 calories from your TDEE. This creates a safe deficit that results in approximately 0.5 kg (1 lb) of fat loss per week without excessive muscle loss.

Target calories = TDEE − 500

Avoid deficits larger than 1,000 kcal/day — anything beyond that risks muscle breakdown, nutrient deficiencies, and metabolic adaptation.

Step 4: Set Your Macro Split

For weight loss, a 35% protein / 35% carbs / 30% fat split is evidence-based and works well for most people:

• Protein (35%): Target calories × 0.35 ÷ 4 = grams of protein
• Carbs (35%): Target calories × 0.35 ÷ 4 = grams of carbs
• Fat (30%): Target calories × 0.30 ÷ 9 = grams of fat

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Step-by-step macro calculation example for a 70kg woman — BMR → TDEE → deficit → macro grams

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Vertical step-by-step infographic. 4 steps connected by arrows. Step 1: 'BMR = 1,401 kcal' (icon: person resting). Step 2: 'TDEE = 2,172 kcal' (icon: person walking). Step 3: 'Target = 1,672 kcal' (icon: minus sign). Step 4: 'Protein 146g | Carbs 146g | Fat 56g' (three coloured bars). Subtitle: '30-year-old woman, 165cm, 70kg, moderately active'. Clean flat design, green/blue/orange palette, white background.

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Example Calculation

For a 30-year-old woman, 165 cm, 70 kg, moderately active, wanting to lose weight:

• BMR = (10 × 70) + (6.25 × 165) − (5 × 30) − 161 = 1,401 kcal
• TDEE = 1,401 × 1.55 = 2,172 kcal
• Target = 2,172 − 500 = 1,672 kcal
• Protein: 1,672 × 0.35 ÷ 4 = 146g
• Carbs: 1,672 × 0.35 ÷ 4 = 146g
• Fat: 1,672 × 0.30 ÷ 9 = 56g

Best Foods for Hitting Your Macros

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Flat-lay of high-protein macro-friendly foods: chicken, eggs, Greek yogurt, tuna, cottage cheese

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Overhead flat-lay food photography on a light grey marble surface. Arrange: grilled chicken breast, 3 eggs, small bowl of Greek yogurt, tin of tuna, small dish of cottage cheese, and a handful of almonds. Clean natural lighting, food styling with minimal props. Text overlay at top: 'High-Protein Macro Foods'. Lifestyle fitness brand aesthetic.

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High-protein foods: Chicken breast, Greek yogurt, eggs, cottage cheese, tuna, whey protein

Complex carbs: Brown rice, oats, sweet potato, quinoa, whole grain bread

Healthy fats: Avocado, olive oil, nuts, salmon, eggs

How to Track Your Macros

1. Get a kitchen scale — portion sizes are rarely what you think they are
2. Use a tracking app — MyFitnessPal and Cronometer both have large food databases
3. Log everything for the first 2–4 weeks to build awareness
4. Prioritise protein first — if you're short on time, just track protein

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MyFitnessPal macro tracking diary showing protein, carbs and fat targets vs. actual intake

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Clean mockup of a mobile nutrition tracking app screen. Shows daily food diary with three macro rings at top: Protein 142g/146g (green, almost full), Carbs 138g/146g (blue), Fat 52g/56g (orange). Meals listed below: Breakfast, Lunch, Dinner, Snacks. Clean white UI, modern fitness app aesthetic. Add 'MyMacroFit' logo in corner.

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Common Mistakes to Avoid

• Not tracking liquids — protein shakes, milk, juice, and alcohol all count
• Eyeballing portions — measuring for just 1–2 weeks teaches you accurate portion sizes forever
• Being too rigid — hitting within ±5–10g of each macro target is close enough
• Changing too quickly — give any macro adjustment 3–4 weeks before tweaking

When to Adjust Your Macros

Reassess your numbers every 4–6 weeks, especially if:

• You've lost or gained more than 5 kg
• Progress has stalled for 3+ weeks
• Your activity level has changed significantly

A drop of 100–200 kcal/day (while maintaining protein) is usually enough to restart progress if weight loss stalls.

Frequently Asked Questions

Can I eat any foods as long as I hit my macros? Yes — "flexible dieting' or IIFYM (If It Fits Your Macros) is a valid approach. That said, whole foods provide better micronutrients and satiety, so aim for 80% whole foods and 20% flexibility.

Do I need to hit macros exactly every day? No. Weekly averages matter more than daily perfection. If you're under on protein one day, make it up the next.

Should I eat back exercise calories? If you calculated your TDEE using an activity multiplier, your exercise is already factored in. Only eat back calories if you used a sedentary multiplier and added significant activity.