Protein Intake Calculator
Find your personalized daily protein target for building muscle based on body weight and activity level. Useful for athletes, gym beginners, and anyone structuring a high-protein diet.
About this calculator
Dietary protein supplies the amino acids your muscles need to repair and grow after training. This calculator uses the formula: Protein (g/day) = weight (kg) × activity multiplier × 1.6. The 1.6 g/kg baseline reflects the scientific consensus upper threshold for maximally stimulating muscle protein synthesis, as supported by a 2018 meta-analysis by Morton et al. The activity multiplier scales intake upward for more demanding training schedules — a sedentary individual might use 1.0 while a competitive athlete might use 1.2 or higher. Distributing your total across 3–5 meals of 25–40 g each maximizes the muscle protein synthesis response throughout the day.
How to use
Suppose you weigh 80 kg and have a moderate activity level with a multiplier of 1.0. The formula gives: Protein = 80 × 1.0 × 1.6 = 128 g per day. If your activity multiplier rises to 1.2 (e.g., training 5 days a week intensely): Protein = 80 × 1.2 × 1.6 = 153.6 g per day. To hit 128 g across four meals, aim for roughly 32 g of protein per meal — equivalent to about 130 g of chicken breast or 5 large eggs per sitting.
Frequently asked questions
How much protein per kilogram of body weight do I actually need to build muscle?
Current evidence supports a target of roughly 1.6–2.2 g of protein per kilogram of body weight per day for individuals seeking muscle hypertrophy. The 1.6 g/kg figure represents the point at which most people reach near-maximal muscle protein synthesis stimulation. Going above 2.2 g/kg is not harmful but provides diminishing returns for muscle gain. Leaner individuals and those in a caloric deficit may benefit from sitting at the higher end of the range.
Does the type of protein source affect how much I need to eat for muscle growth?
Yes, protein quality matters. Complete proteins containing all essential amino acids — found in animal sources like meat, eggs, and dairy, and in soy — are more efficiently used for muscle building than incomplete plant proteins. If you rely heavily on plant sources such as rice, beans, or wheat, you may need to eat toward the upper end of the recommended range and combine complementary sources to cover all essential amino acids. Leucine content is particularly important, as it acts as the primary trigger for muscle protein synthesis.
When is the best time to eat protein to maximize muscle gain?
Spreading protein evenly across 3–5 meals throughout the day is more effective than consuming it all in one or two sittings. Each meal should ideally contain 0.4 g/kg of body weight (roughly 25–40 g for most people) to maximally stimulate a muscle protein synthesis response. A dose within 1–2 hours post-workout is widely recommended, though recent research suggests the total daily intake matters more than precise timing for most recreational athletes. A slow-digesting protein like casein before bed can also support overnight muscle repair.