MacroMath

nutrition

Bulking macros calculator

Weight unit

Advertisement
Read more

What is a bulking phase?

A bulk is a period of eating above maintenance to support muscle growth. The surplus provides extra energy and nutrients for muscle protein synthesis. The trade-off is that some fat gain is unavoidable — the surplus type you choose controls how much.

How to use this calculator

  • Enter your TDEE, weight, and body fat percentage.
  • Choose your bulk type: lean (+200 kcal), standard (+350 kcal), or aggressive (+500 kcal).
  • Click Calculate Bulking Macros to see your targets.

The formula

Calories = TDEE + surplus
  Lean:       +200 kcal/day
  Standard:   +350 kcal/day
  Aggressive: +500 kcal/day

Protein = lean body mass (kg) × 2.2 g/kg
Fat     = 25% of calories ÷ 9 kcal/g
Carbs   = remaining calories ÷ 4 kcal/g

Weekly gain ≈ surplus × 7 ÷ 7,700 kcal/kg

How to interpret your result

Most of the weekly gain number is muscle at realistic surpluses — but expect 30–50% to be fat. If you're gaining more than 0.5–1% of bodyweight per week, reduce the surplus. Track progress every 2 weeks and adjust accordingly.

Related tools

Frequently asked questions

How much surplus do I need to build muscle?

Lean bulk: 5–10% above TDEE. Standard bulk: 10–15%. Aggressive bulk: 15–20%. Bigger surpluses add fat faster without adding more muscle — natural lifters rarely benefit beyond 300 kcal over maintenance.

How fast should I gain weight while bulking?

0.25–0.5% of bodyweight per week for experienced lifters. Beginners can push 0.5–1%. Gaining faster means more fat per kilo of muscle.

Related calculators