Macro Calculator for Bulking
Bulking macros: optimal nutrient distribution to maximize muscle mass gain.
What macros in a bulking phase?
The bulking phase creates the hormonal and energetic conditions for maximum muscle growth. Carbohydrates are the starring macronutrient: they raise insulin (anabolic hormone), replenish muscle glycogen and sustain performance during high-intensity training [¹]. A surplus of 200–400 kcal/day above TDEE is sufficient for a lean bulk — a larger surplus only means more fat without greater muscle growth [²]. Bulking ratio: 20–25% protein / 50–55% carbs / 20–25% fat.
How to use this calculator for bulking
Select 'Bulk' goal and 'Medium' or 'High' protein. The applied surplus (~300 kcal) is calibrated for a lean bulk. Beginners (<2 years training) can use a larger surplus (~500 kcal) because muscle synthesis capacity is higher. Advanced lifters should stay near 200–250 kcal surplus.
Macro distribution for bulking by training level
| Level | Recommended surplus | Protein | Carbs | Fat |
|---|---|---|---|---|
| Beginner (<1 year) | 400–500 kcal | 1.8 g/kg | 55% | 22% |
| Intermediate (1–3 years) | 250–350 kcal | 2.0 g/kg | 52% | 23% |
| Advanced (>3 years) | 150–250 kcal | 2.2 g/kg | 50% | 25% |
FAQ
1How much weight should I gain per week when bulking?
0.25–0.5 kg/week for beginners; 0.1–0.25 kg/week for intermediate and advanced lifters. Faster gains indicate more fat than muscle is being accumulated [²].
2Is there a difference between a lean bulk and a dirty bulk?
Yes. A dirty bulk (no calorie control) accelerates fat gain without accelerating muscle growth [²]. Muscle protein synthesis has a physiological ceiling that more food does not overcome. A lean bulk optimises the muscle-to-fat ratio.
3How long should a bulking phase last?
Generally 4–6 months, until body fat exceeds 15–18% for men or 23–26% for women. Beyond that, insulin sensitivity worsens and anabolism decreases [³].
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