Macro Calculator — Protein, Carbs & Fat

Macronutrient ratios divide your daily calories among protein, carbohydrates and fat. Common starting points are 30/40/30 (balanced), 40/30/30 (high protein for muscle gain) or 25/45/30 (endurance). Each gram of protein and carbohydrate provides 4 kcal, while fat provides 9 kcal.

This calculator first estimates your Total Daily Energy Expenditure, then splits those calories into grams of each macronutrient based on your chosen goal. For weight loss, protein is kept high (around 30–40%) to preserve muscle mass, while carbohydrates and fat are reduced. For muscle gain, both protein and carbohydrates are elevated.

Macro tracking is widely used alongside calorie counting to improve body composition. The NHS recommends that fat should not exceed 35% of total energy and that saturated fat should stay below 11%. Adjust ratios to suit your preferences and monitor progress over several weeks.

What are macronutrients? Three energy-providing nutrients: protein, carbohydrates, fat. Protein 4 kcal/g, carbs 4 kcal/g, fat 9 kcal/g. Alcohol 7 kcal/g (4th macro, technically). Each plays different role: protein builds/repairs muscle and tissue; carbs primary energy source; fat hormones, vitamin absorption, energy storage. UK government Eatwell Guide recommends: 50% carbs, 35% fat, 15% protein. Fitness/weight-loss communities often recommend higher protein (25-35%) and lower carbs.

Calculating your macro split. Step 1: calculate TDEE (typical 2,000-3,000 kcal/day depending on size/activity). Step 2: set protein based on body weight (1.6-2.2g per kg). Step 3: set fat (0.6-1.0g per kg, minimum 30g/day). Step 4: remaining calories from carbs. Sample 70kg adult, 2,200 kcal: protein 140g (560 kcal); fat 60g (540 kcal); carbs 1,100 kcal = 275g. Total daily: 140P/275C/60F.

UK macro food sources. Protein (best UK sources): chicken breast 31g/100g; turkey 29g; tuna 28g; salmon 25g; eggs 13g/100g (6g per egg); Greek yogurt 10g; cottage cheese 12g; lentils 9g cooked; chickpeas 9g; tofu 8g; whey protein 20-25g/scoop. Carbs (UK favourites): oats 60g/100g; brown rice 70g cooked; potatoes 17g/100g; sweet potatoes 20g; wholewheat bread 40g (slice 10-15g); bananas 23g each; apples 14g each. Fats: olive oil 100g/100g; avocado 15g/100g; almonds 50g; walnuts 65g; salmon 13g.

Macros for specific goals. Weight loss (moderate): 40% protein, 30% carbs, 30% fat — protein high to preserve muscle. Muscle gain (bulking): 25% protein, 45% carbs, 30% fat — carbs fuel training. Endurance training (running, cycling): 20% protein, 55% carbs, 25% fat — carbs critical for glycogen. Maintenance/general health: NHS Eatwell 15-50-35 P-C-F. Keto: 5-25% protein, 5-10% carbs, 65-90% fat (extreme low-carb). Mediterranean (heart-healthy): moderate protein, lots of carbs from veg/legumes, fats from olive oil/nuts.

Tracking macros — apps and methods. Apps: MyFitnessPal (free, largest UK food database), Cronometer (more accurate nutrient data), Lifesum, Carb Manager. Food scale £5-£15 essential — eyeballing portions off by 30-50%. Pre-log meals in advance: stick to plan, avoid impulse decisions. Don't track to gram-perfect — ±10% acceptable. Focus on protein hits first; carbs/fats less precision needed. Use 'meal prep' approach: same breakfast and lunch on workdays simplifies tracking. Weigh raw vs cooked weight: oats 50g raw = 200g cooked (water absorbed) — track raw weight.