Daily Protein Intake Calculator (g/kg)

Daily protein per kg of body weight

The math is about as simple as it gets: proteing/day = weightkg × targetg/kg. What changes is the target, and the ISSN (International Society of Sports Nutrition) consensus lays out reference ranges by activity and goal. If you are sedentary, 0.8 g/kg is the RDA floor, enough to avoid a deficiency and not much more. Recreational exercise pushes you to 1.2-1.6 g/kg, strength and endurance athletes sit at 1.6-2.2 g/kg, and someone in a caloric deficit or cutting climbs to 2.2-2.8 g/kg, which helps hold on to lean mass while energy is restricted. The elderly need 1.2-1.5 g/kg to fight sarcopenia. Past 2.5 g/kg, there is no proven extra benefit. How you spread it across the day also counts: 0.3-0.4 g/kg per meal clears the leucine threshold (~2.5 g) that drives muscle protein synthesis the hardest. Whey is fast, so it works post-workout; casein is slow, which suits the hours before sleep. Take an 80 kg athlete cutting at 2.4 g/kg: 80 × 2.4 = 192 g/day, divided into 4 meals of 48 g.

Applications: sports, geriatrics and bariatrics

Sports nutrition uses it to plan hypertrophy and recovery. In geriatrics it helps stave off sarcopenia, since older adults need more protein per kg than a younger sedentary person does. After bariatric surgery, follow-up aims for 60-120 g/day to protect lean mass while the patient loses weight fast. It also comes up in chronic kidney disease, where intake is usually held back rather than pushed up, and in vegetarian or vegan planning, where you have to check both the total and the amino-acid profile.

FAQ

Does extra protein damage the kidneys? Not in healthy people. Studies have looked at intakes as high as 3 g/kg without finding renal harm. If you already have kidney disease, though, a nephrologist needs to set the amount for you individually.

Should I use total weight or lean mass? Total weight works fine for most people. For someone who is obese, basing the figure on lean body mass (or a target weight) keeps you from overshooting what is actually needed.

Can I get it all from food? Yes. A supplement like whey is handy, but nothing forces you to use one. Eggs, chicken, fish, beef, dairy, legumes and tofu will cover even a high target without much trouble.

Why split across meals? Around 25-40 g of protein at once gives muscle protein synthesis its biggest push, so spreading your intake over 3-5 meals does more than dumping it all into one giant serving.