Daily protein target by body weight and goal — enter weight in any unit.
Daily Protein (g) = W_kg × F
The most widely used method for estimating daily protein needs multiplies your body weight in kilograms by a protein factor (g/kg) that varies by activity level and goal:
The formula is straightforward: multiply your weight in kilograms by the appropriate factor. If you enter weight in pounds, the calculator first converts to kilograms by dividing by 2.2046.
Disclaimer: This calculator is for educational purposes only and does not constitute medical or nutritional advice. Consult a registered dietitian or physician before making significant dietary changes.
W_kg = 180 ÷ 2.2046 = 81.65 kg Daily Protein = 81.65 kg × 2.2 g/kg = 179.6 g ≈ 180 g
Result: ~180 grams of protein per day
A 180-pound person who lifts weights six days a week with a muscle-building goal should aim for approximately 180 grams of protein per day. This works out to roughly 1.0 g per pound of body weight, which aligns with the practical guideline commonly cited by sports nutritionists. Spread across 4–5 meals or snacks, that is about 36–45 g of protein per eating occasion — achievable through lean meats, eggs, dairy, legumes, or protein supplements.
Protein is a macronutrient composed of amino acids — the building blocks for muscle tissue, enzymes, hormones, and immune system components. Unlike carbohydrates and fat, the body has no dedicated storage depot for protein, which is why meeting a daily target consistently is important.
The Recommended Dietary Allowance (RDA) for protein in sedentary healthy adults is 0.8 g/kg/day, established by the Institute of Medicine. However, multiple meta-analyses and position statements from sports nutrition organizations show that:
Not all protein sources are equal. Complete proteins (containing all essential amino acids) include animal products (chicken, beef, fish, eggs, dairy) and some plant sources (soy, quinoa). Incomplete proteins (most plant sources) can be combined throughout the day to meet amino acid needs.
Research suggests spreading protein intake across 3–5 meals maximises muscle protein synthesis. Consuming 20–40 g of high-quality protein per meal (roughly the threshold for maximally stimulating synthesis) and including a protein-rich snack before bed (e.g., casein) may support overnight muscle repair.
High protein intakes (up to 3.5 g/kg/day) are generally safe in healthy adults with normal kidney function. Those with pre-existing kidney disease should consult a physician before increasing protein intake significantly.
The densest protein sources include canned tuna (~30 g/100 g), chicken breast (~31 g/100 g), low-fat cottage cheese (~11 g/100 g), Greek yogurt (~10 g/100 g), lentils (~9 g/100 g cooked), and whey protein powder (~75–80 g/100 g).
Protein provides 4 calories per gram. If your daily protein target is 180 g, that contributes 720 calories. Knowing this helps you allocate the remaining calorie budget between carbohydrates and fats when planning your overall macros.
Yes — protein needs actually **increase** during a caloric deficit. Eating 2.3–3.1 g/kg of lean body mass helps preserve muscle tissue while the body is in an energy deficit, which is why the calculator uses a higher factor (2.4 g/kg) for a fat-loss or recomposition goal.
Plant proteins can be equally effective when total daily intake is sufficient and a variety of sources are consumed to ensure all essential amino acids are present. Leucine content is the key driver of muscle protein synthesis, so plant-based athletes may need slightly higher total protein to match the leucine from animal sources.
For muscle gain, most sports nutrition research supports 1.6–2.2 g of protein per kg of body weight per day (roughly 0.7–1.0 g per pound). The calculator applies a factor of 2.2 g/kg for a muscle-building goal combined with heavy training.
Yes — 1 g per pound (≈ 2.2 g/kg) is a widely used practical guideline for strength athletes and bodybuilders. It is slightly above the upper end of what research identifies as strictly necessary, but it is safe for healthy adults and provides a comfortable margin.
If you are significantly overweight, consider basing the calculation on your **goal weight** or **lean body mass** to avoid greatly overestimating needs. The calculator uses current total body weight, which is the most common approach and acceptable for most users.
In healthy adults without kidney disease, intakes up to approximately 3.5 g/kg/day appear safe. Beyond meeting your target, excess protein is used for energy rather than additional muscle building. Very high intakes may crowd out other important macronutrients and add unnecessary calories.
Yes. Adults over 65 typically need at least 1.2 g/kg/day — and often 1.6 g/kg or more — to counteract age-related muscle loss (sarcopenia). The calculator's 'moderately active' or 'very active' factor is usually appropriate for active older adults.
Only sources that have been reviewed are shown. Unverified citations are never published.