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Bulking Calculator

Calculate your optimal bulking calories, daily protein target, and complete macro split for lean muscle gain. Choose your surplus size — from lean bulk to aggressive surplus. Supports kg/lbs.

Bulking Phase Calculator

TDEE · Surplus · Protein · Full macro split

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Daily Bulking Calories

The bulking calculator estimates your TDEE using the Mifflin-St Jeor equation, adds your chosen surplus, and calculates a macro split prioritising protein for muscle protein synthesis, with remaining calories distributed between carbs and fats.

Bulking Surplus Options

Surplus TypeExtra CaloriesExpected GainBest For
Lean Bulk+150–200 kcal/day0.1–0.15 kg/weekLow fat gain priority; advanced lifters
Standard+250–300 kcal/day0.2–0.25 kg/weekBest muscle-to-fat ratio
Moderate+400–500 kcal/day0.3–0.4 kg/weekFaster gains, some fat acceptable
Aggressive+700–1,000 kcal/day0.7–1 kg/weekFast total mass; significant fat gain

Lean Bulk vs. Dirty Bulk — What the Science Says

A common misconception is that a larger caloric surplus leads to more muscle growth. In reality, muscle protein synthesis (MPS) has a ceiling rate that is independent of calorie surplus size. Beyond 300–400 kcal/day above TDEE, additional calories overwhelmingly go to fat storage. Brad Schoenfeld's research indicates that 0.4–0.7 g/kg/day protein combined with resistance training maximises MPS — additional food beyond energy needs adds little to this process.

The advantage of dirty bulking (eating large surpluses freely) is purely psychological — it is easier and more enjoyable. The disadvantage is a prolonged and difficult cut afterwards. Most lifters who dummy-bulk at 1,000+ kcal/day find themselves needing 20–24 week cuts to undo 4 months of excessive fat gain — wasting time that could have been spent at a comfortable body fat with steady muscle growth.

Frequently Asked Questions

Effective bulking phases are typically 4–6 months in length. This provides enough time for meaningful muscle accumulation (1–4 kg lean mass depending on experience level) while keeping body fat growth manageable. Most fitness experts recommend stopping a bulk when body fat reaches 18–20% for men and 28–30% for women, as higher fat levels impair anabolic hormone balance.
1.6–2.2 g of protein per kg of body weight per day is sufficient for maximising muscle protein synthesis during a bulk. Higher intakes (2.5–3 g/kg) offer no additional benefit for muscle gain but may help with satiety. Spread protein across 4–5 meals of 30–50 g each. Leucine-rich sources (whey, eggs, chicken, fish) are particularly effective at stimulating MPS.
Creatine monohydrate is the most well-researched sports supplement with the strongest evidence base. It consistently increases strength by 5–15%, power output, and high-intensity work capacity — all of which drive greater training adaptations. 3–5 g/day of creatine monohydrate (no loading needed) is the standard dose. Note: creatine causes water retention of 1–2 kg within 2–4 weeks, which is not fat and will be lost if you stop taking it.
Yes, in specific circumstances. Body recomposition (simultaneously losing fat and gaining muscle) is achievable for: (1) Complete beginners to resistance training; (2) Previously trained individuals returning after a break; (3) People with higher body fat levels (>25% for men, >32% for women). In these cases, fat provides the extra energy, allowing muscle to be built at maintenance or even slight deficit calories. Advanced, lean, experienced lifters cannot recomp effectively and require a dedicated surplus to gain muscle.
Best bulking foods: Protein — chicken, beef, salmon, tuna, eggs, Greek yogurt, cottage cheese, whey. Carbs — rice, potatoes, oats, pasta, bread, fruit. Fats — avocado, olive oil, nuts, nut butters, eggs. Calorie-dense foods for struggling to hit targets: whole milk, granola, nuts, nut butters, dried fruit, avocados, oils. Avoid relying on junk food — ultra-processed foods impair recovery, gut health, and hormone production even when calories are matched.

Related Calculators

Cutting CalculatorDeficit calories and macros for fat loss phase.Calculate → Calorie Surplus CalculatorFind your exact surplus for lean muscle gain.Calculate → Muscle Mass CalculatorEstimate lean muscle mass and natural potential.Calculate → Caloric Needs CalculatorYour TDEE — maintenance calorie baseline.Calculate →