Bulking Calorie Surplus Calculator
Turn your maintenance calories into a lean-bulk or standard-bulk target from a chosen weekly rate of weight gain.
How it works
Daily surplus = weekly gain(kg) × 7700 ÷ 7 · Target = maintenance + surplus
Building muscle requires eating above maintenance, but bigger surpluses do not build muscle faster — they mostly add fat, because the rate of muscle growth is capped by training and recovery. A lean bulk uses a modest surplus (often 0.25 kg/week or less) so most of the added weight is muscle. This tool converts your chosen weekly gain into the daily calorie surplus and target, using the 7,700 kcal-per-kg energy constant.
Worked example
On 2,500 kcal maintenance with a 0.25 kg/week lean-bulk goal, the surplus is 0.25 × 7700 ÷ 7 ≈ 275 kcal/day, so the target is 2,500 + 275 ≈ 2,775 kcal per day.
Frequently asked questions
How big should a bulking surplus be?
For most trainees a small surplus of roughly 10–20% above maintenance (often 200–500 kcal) is enough to build muscle while limiting fat gain. Beginners and those returning from a break can gain a little faster; advanced lifters should stay leaner.
Will eating more make me gain muscle faster?
Only up to a point. Muscle growth is limited by your training stimulus, recovery and genetics, so calories beyond what supports that growth are stored mainly as fat. Pair the surplus with progressive resistance training and adequate protein.
How much protein while bulking?
Around 1.6–2.2 g per kg of body weight per day supports muscle growth. Use a protein intake calculator to set your target, then fill the rest of your calories with carbohydrates and fats.
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Educational estimate only — not medical, dietary or fitness advice. Individual needs vary; consult a qualified clinician or registered dietitian before making health decisions.