Protein Calculator
Calculate your recommended daily protein intake in grams based on body weight and fitness goal.
About the Protein Calculator
Protein needs scale with body weight and activity level far more than with total calories alone — someone strength training regularly needs meaningfully more protein per kilogram than someone with a sedentary lifestyle. This calculator gives a daily gram target based on your weight and goal.
How It Works
The calculator multiplies your body weight in kilograms by a protein factor that scales with your selected goal — a modest factor for general maintenance, a higher factor for regularly active people, and the highest factor for those actively building muscle.
Daily Protein (g) = Weight (kg) × Factor, where factor is about 1.2 (maintenance), 1.6 (active), or 2.0 (build muscle).
Worked example
Scenario: A 70 kg adult who exercises regularly (active, 1.6 g/kg).
- Choose the factor for the goal: 1.6 g per kg for active people.
- Multiply by body weight: 70 × 1.6 = 112 g a day.
- For comparison, the basic adult RDA of 0.8 g/kg is 56 g.
Result: About 112 g of protein a day.
Tips and common mistakes
- Spreading protein over 3–4 meals of 25–40 g each is a practical way to reach the total.
- Enter weight in kilograms (lb ÷ 2.205).
- People with kidney disease should follow medical advice on protein intake.
Assumptions & Limitations
- Factors are based on commonly cited sports-nutrition research ranges for protein needs relative to body weight.
- Uses total body weight rather than lean body mass, which is simpler but slightly overestimates needs for individuals with higher body fat percentages.
- Individuals with kidney conditions or other specific medical concerns should consult a healthcare provider before significantly increasing protein intake.
- Protein timing and distribution across meals also affects muscle protein synthesis, which this simple daily total does not address.
Protein targets need context
The adult protein RDA is 0.8 g/kg/day for generally healthy adults. People doing regular resistance training often consume more; a large meta-analysis found that gains in fat-free mass during resistance training did not continue to increase beyond about 1.6 g/kg/day on average. That does not make 1.6 g/kg a universal prescription.
Needs can differ with age, total energy intake, training, pregnancy, illness and kidney disease. This calculator is intended as a planning estimate for healthy adults, not individualized nutrition or medical advice.
Sources and review
Method: Body weight (kg) × a goal factor: 1.2, 1.6 or 2.0 g/kg, compared with the 0.8 g/kg adult RDA.
Sources:
- National Academies (Institute of Medicine), Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids, 2005.
- Jäger R, et al. International Society of Sports Nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition, 2017;14:20.
Last reviewed: October 2026 by Faheem Ali, founder of CalculatorAnything. The method and examples are provided for transparency; results remain estimates and may contain errors.
Results are estimates for general information and screening, not a diagnosis or medical advice. Talk to a qualified healthcare professional before making health or diet decisions. Spotted an error? Tell us — see our editorial policy for how corrections are handled.