Formula
Protein (g/day) = body weight (kg) × g/kg factorg/kg factor depends on activity and goal (0.8 – 2.4) How it works
Protein supplies the amino acids your body uses to build and repair muscle, skin, enzymes and hormones. The official Recommended Dietary Allowance for adults is 0.8 g per kilogram of body weight — enough to prevent deficiency in most sedentary people, but not necessarily optimal for active ones.
Research on athletes supports higher intakes: roughly 1.2–1.6 g/kg for endurance training and 1.6–2.2 g/kg for building muscle. During a calorie deficit, even higher intakes help preserve lean tissue. Older adults also benefit from a little more than the RDA to slow age-related muscle loss.
Spreading protein over several meals of roughly 20–40 g each appears to support muscle growth better than eating it all at once. If you carry a lot of excess body fat, using your goal weight instead of current weight gives a more realistic target.
Frequently asked questions
Is a high-protein diet safe?
For healthy adults, intakes up to about 2 g/kg appear safe in long-term studies. People with kidney disease need individual advice because their kidneys may not handle extra protein well.
How much protein is in common foods?
Roughly: 100 g cooked chicken breast ≈ 31 g, one large egg ≈ 6 g, 170 g Greek yogurt ≈ 17 g, 100 g cooked lentils ≈ 9 g, 100 g firm tofu ≈ 15 g.