What are macros?
Macronutrients — or "macros" — are the three main nutrients that provide your body with energy: protein, carbohydrates, and fat. Every food you eat contains some combination of these three nutrients. Understanding and tracking your macros gives you far more control over your body composition than simply counting calories alone.
Here's how each macro breaks down in terms of calories per gram:
| Macronutrient | Calories per gram | Primary role |
|---|---|---|
| 🥩 Protein | 4 calories/gram | Muscle building and repair, satiety |
| 🌾 Carbohydrates | 4 calories/gram | Energy, brain function, performance |
| 🥑 Fat | 9 calories/gram | Hormones, brain health, vitamin absorption |
Step 1 — Calculate your BMR
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to keep your heart beating, lungs breathing, and organs functioning. It's the foundation of all macro calculations.
The most accurate formula for calculating BMR is the Mifflin-St Jeor equation, which has been validated in multiple peer-reviewed studies:
Mifflin-St Jeor Formula
For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Example: A 30-year-old man, 180cm, 80kg → BMR = (10×80) + (6.25×180) − (5×30) + 5 = 800 + 1,125 − 150 + 5 = 1,780 calories
Step 2 — Find your TDEE
Your Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor. This represents the total calories you burn each day including exercise, movement, and daily activity.
| Activity level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise, desk job | × 1.2 |
| Lightly active | Light exercise 1–3 days/week | × 1.375 |
| Moderately active | Moderate exercise 3–5 days/week | × 1.55 |
| Very active | Hard exercise 6–7 days/week | × 1.725 |
| Extra active | Very hard exercise or physical job | × 1.9 |
Using our example above: 1,780 × 1.55 (moderately active) = 2,759 calories TDEE. This is the maintenance level — eating this keeps weight stable.
Step 3 — Adjust for your goal
Once you have your TDEE, adjust your calorie target based on what you want to achieve:
- Weight loss: Eat 15–20% below TDEE (e.g. 2,759 × 0.8 = 2,207 calories)
- Maintenance: Eat at TDEE (2,759 calories)
- Muscle gain: Eat 5–10% above TDEE (e.g. 2,759 × 1.1 = 3,035 calories)
Step 4 — Set your macro split
Now distribute your calories across the three macronutrients. Here are the recommended splits by goal:
| Goal | Protein | Carbs | Fat |
|---|---|---|---|
| 🔥 Weight loss | 40% | 30% | 30% |
| ⚖️ Maintenance | 30% | 40% | 30% |
| 💪 Muscle gain | 30% | 45% | 25% |
To convert percentages to grams: multiply your total calories by the percentage, then divide by the calories per gram (4 for protein and carbs, 9 for fat).
Example calculation (weight loss, 2,207 calories)
Protein: 2,207 × 0.40 ÷ 4 = 221g protein
Carbs: 2,207 × 0.30 ÷ 4 = 166g carbs
Fat: 2,207 × 0.30 ÷ 9 = 74g fat
Step 5 — Track and adjust
Use a food tracking app like MyFitnessPal, Cronometer, or MacroFactor to log your daily intake. Weigh your food with a kitchen scale for the first 2–4 weeks until you can accurately estimate portions by eye.
Reassess your macros every 4 weeks based on progress. If you're losing weight faster than 1–2 lbs per week, add 100–200 calories. If you're not losing weight after 2 consistent weeks, reduce by 100–200 calories.