Protein Intake Calculator

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How This Calculator Works

This calculator uses the Mifflin-St Jeor equation combined with activity multipliers and goal-specific adjustments. For muscle gain, we apply a 1.6-2.2 g/kg multiplier. For fat loss (cutting), we increase protein to 1.8-2.4 g/kg to preserve lean mass. If you enter body fat percentage, we calculate lean body mass and base protein targets on that instead of total weight — more accurate for people with higher body fat.

The science: The International Society of Sports Nutrition (ISSN) position stand recommends 1.4-2.0 g/kg for most athletes, with higher intakes (up to 2.4 g/kg) during calorie deficits. This calculator implements those ranges with practical rounding.

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