How it works
Protein needs scale with body size and goal. This calculator uses ranges rather than a single number because individual needs vary with training volume, diet quality, age, and total calorie intake.
The ranges are:
- General health / sedentary: 0.8 g per kg body weight — the RDA level for basic health.
- Build muscle or maintain weight: 1.6–2.2 g per kg body weight — the range most often associated with maximizing muscle protein synthesis in trained people.
- Fat loss while preserving muscle: 2.3–3.1 g per kg body weight — higher intakes help protect lean mass when calories are low.
If you enter a body-fat percentage, the calculator also estimates your fat-free mass and can display the target relative to lean tissue. For most people, the per-kilogram-of-body-weight range is simpler and sufficiently accurate.
Limitations
These targets assume you are eating mixed, complete protein sources spread across the day. Vegetarians and vegans may benefit from aiming toward the higher end of a range because plant proteins are often lower in leucine and other essential amino acids per gram. Kidney disease, pregnancy, and certain medical conditions require individualized guidance.