How it works
The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day. That is the minimum to prevent deficiency in healthy sedentary adults, not necessarily the best intake for everyone.
Active people use more. Position stands from the International Society of Sports Nutrition and the American College of Sports Medicine suggest roughly 1.2–2.0 g/kg for athletes, with 1.6–2.2 g/kg common for building muscle. Research also supports around 1.0–1.2 g/kg for adults over 65 to help maintain muscle.
If you have kidney disease or another condition affecting protein needs, follow your clinician's guidance. Results are estimates, not medical advice.
Formula
Daily protein (g) = body weight (kg) × g/kg for your activity level
Questions people ask
How much protein do I need per day?
At least 0.8 g per kg (about 0.36 g per lb) for a sedentary adult. Regular exercisers often do well at 1.2–1.6 g/kg, and people strength training to build muscle at 1.6–2.2 g/kg.
Is it better to spread protein across meals?
Research suggests muscle protein synthesis responds well to roughly 20–40 g of protein per meal, so spreading intake over three to five meals is a sensible approach.
Can I eat too much protein?
For healthy adults, intakes up to about 2 g/kg appear safe in studies. People with existing kidney disease may need to limit protein and should follow medical advice.
Should I use my current or goal weight?
For people carrying significant extra body fat, using a goal or adjusted body weight avoids overestimating needs, because fat tissue does not need protein the way muscle does.