Protein Calculator — Free

For weight loss: a calorie deficit is the one setting where eating more protein matters most. Set the goal to Weight loss and the calculator targets 1.8–2.4 g/kg (about 0.8–1.1 g/lb) — high enough to protect lean muscle so the weight you lose is fat, blunt hunger, and raise the calories you burn digesting food. As a worked example, a sedentary 90 kg person dieting lands around 189 g/day; a 70 kg person around 147 g/day — more if they train (the calculator shifts the band up with activity).

For muscle gain and muscle growth: choose Muscle gain for a 1.6–2.2 g/kg target (about 0.7–1.0 g/lb). Research shows muscle-building benefits plateau near 1.6 g/kg for most people and around 2.2 g/kg for hard-training lifters — going higher doesn't build extra muscle, so the calculator caps the range there and you pair it with progressive resistance training.

Protein calculator for weight loss — women: protein needs scale with body weight and lean mass, not sex, so the same g/kg bands apply to women. A woman losing weight uses the same 1.8–2.4 g/kg target — e.g. a 65 kg woman ≈ 117–156 g/day, recommended ~137 g. Because women carry more essential fat, the optional lean-mass method (enter your body fat %) often gives a slightly lower, sharper number than body weight alone. Higher protein is just as protective of muscle for women as for men during a diet.

The simplest way to set a protein target is per kilogram of body weight — quick, and accurate enough for most people. Its blind spot is body composition: two people at 90 kg, one lean and one carrying a lot of fat, get the same target even though fat tissue is metabolically quiet and doesn't need protein to maintain it.

The fix is the lean-mass method. If you know your body fat percentage, the calculator works out your lean body mass (weight × (1 − body fat%)) and applies 2.3–3.1 g per kg of lean mass — feeding the muscle and organs that actually use protein, and ignoring the fat that doesn't. For lean trainees the two methods land close together; the more body fat you carry, the more the lean-mass method lowers (and sharpens) the number. Don't know your body fat? Estimate it with the Body Fat % Calculator, then come back and enter it.

Protein is the anchor of your diet, but it's only one of three macros. Once you have your gram target:

1. Build the full plate. Lock protein in first, then split the rest of your calories between carbs and fat with the Macro Calculator — it uses the same per-kg protein logic, so the two tools agree.
2. Know your calorie budget. Protein only protects muscle inside the right energy balance — set yours with the TDEE Calculator and a sensible deficit.
3. Spread it out. Aim for 3–4 servings of roughly 0.3–0.4 g/kg each across the day rather than one big hit — that pattern maximises muscle protein synthesis.