Counting calories works for weight loss, but tracking macros (macronutrients) gives you something calories alone cannot: control over body composition. The right macro split preserves muscle while you lose fat, prevents energy crashes, and keeps hunger manageable. Here's how to calculate your targets from scratch.
What Are Macros?
There are three macronutrients, and all calories come from them:
- Protein: 4 calories per gram. Essential for muscle preservation, satiety, and metabolic support during weight loss.
- Carbohydrates: 4 calories per gram. Primary fuel source; includes dietary fibre.
- Fat: 9 calories per gram. Essential for hormones, fat-soluble vitamins, and satiety.
Step 1 — Calculate Your TDEE
Your Total Daily Energy Expenditure (TDEE) is the foundation. Use our TDEE calculator for precision, or estimate:
BMR (Mifflin-St Jeor, men): (10 × kg) + (6.25 × cm) − (5 × age) + 5
BMR (women): (10 × kg) + (6.25 × cm) − (5 × age) − 161
TDEE = BMR × Activity factor (1.2–1.9 depending on exercise level)
Step 2 — Set Your Calorie Deficit
| Goal | Deficit | Expected loss | Best for |
|---|---|---|---|
| Aggressive cut | 750–1,000 kcal/day | 0.75–1 kg/week | Short-term, higher muscle loss risk |
| Moderate deficit | 400–500 kcal/day | 0.4–0.5 kg/week | Sustainable, good muscle retention |
| Conservative | 200–300 kcal/day | 0.2–0.3 kg/week | Athletes, small amounts to lose |
For a 70 kg woman with a TDEE of 2,100 kcal, a 500 kcal deficit gives a target of 1,600 kcal/day.
Step 3 — Set Protein (Priority #1)
Protein is the most important macro during weight loss. High protein intake preserves lean muscle mass and has the highest thermic effect (your body burns 20–35% of protein calories just digesting it).
Target protein: 1.6–2.2 g per kg of bodyweight (1.6 for maintenance, 2.2 for active/heavy training)
Example: 70 kg × 2.0 g = 140 g protein × 4 kcal = 560 kcal from protein
Step 4 — Set Fat (Minimum Floor)
Fat is essential for hormonal health. Going too low (below 0.7 g/kg) can impair testosterone and oestrogen production, affect mood, and reduce absorption of fat-soluble vitamins (A, D, E, K). The practical minimum:
Minimum fat: 0.7–1.0 g per kg bodyweight
Example: 70 kg × 0.8 g = 56 g fat × 9 kcal = 504 kcal from fat
Step 5 — Fill Remaining Calories with Carbohydrates
Carb calories = Total daily calories − Protein calories − Fat calories
Carb grams = Carb calories ÷ 4
Example: 1,600 − 560 − 504 = 536 kcal ÷ 4 = 134 g carbohydrates
Complete Example Macro Target
| Macro | Grams | Calories | % of diet |
|---|---|---|---|
| Protein | 140g | 560 kcal | 35% |
| Fat | 56g | 504 kcal | 31.5% |
| Carbohydrates | 134g | 536 kcal | 33.5% |
| Total | 1,600 kcal | 100% |
Tracking Your Macros
Apps like MyFitnessPal, Cronometer, or Nutracheck UK make tracking straightforward. Weigh food raw (before cooking) unless you use the cooked weight database, which exists but is less accurate. Consistency matters more than precision — aim to be within 10% of your targets daily rather than achieving exact grams.