What is the formula for calculating daily protein intake?

November 19, 2025 •

3 min read

The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight, but your ideal intake can vary significantly based on your lifestyle. Discover the precise formula for calculating daily protein intake tailored to your specific fitness goals and personal requirements.

Quick Summary

Calculating daily protein needs involves multiplying your body weight by a factor determined by your activity level and fitness objectives, such as muscle growth, weight loss, or general health.

Key Points

RDA is a Minimum: The official 0.8 g/kg formula is the Recommended Dietary Allowance (RDA), representing the minimum to prevent deficiency, not the optimal amount for performance or specific goals.
Adjust for Activity: Your protein needs increase significantly with physical activity, requiring a higher intake than a sedentary person for proper muscle repair and recovery.
Goals Dictate Intake: Whether you're aiming for weight loss, muscle gain, or endurance, your specific goal determines the protein factor you should multiply by your body weight.
Age Increases Needs: Older adults and those recovering from injury or illness often require more protein to counteract muscle loss and support healing.
Timing and Distribution Matter: Spreading your protein intake across multiple meals throughout the day, rather than in one or two large servings, can optimize muscle protein synthesis.
Quality is Key: Include high-quality protein sources—both animal-based and complementary plant-based ones—to ensure you consume all essential amino acids.

The Basic Protein Intake Formula: The RDA

For most healthy, sedentary adults, the Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight. This is the minimum amount to prevent deficiency. To use this formula, convert your weight to kilograms by dividing pounds by 2.2.

How to Calculate Your RDA

To determine your minimum daily protein requirement based on the RDA:

Convert Your Weight to Kilograms: Divide your weight in pounds by 2.2. Example: 165 pounds / 2.2 ≈ 75 kg.
Apply the Formula: Multiply your weight in kilograms by 0.8. Example: 75 kg * 0.8 = 60 grams of protein per day.

Adjusting Your Protein for Different Goals

Your protein needs vary based on activity level, age, and body composition goals. The RDA may be insufficient if you are active, aiming to lose weight, or are an older adult.

Protein for Weight Loss

Adequate protein is vital for preserving lean muscle during weight loss in a calorie deficit. It also increases satiety and metabolism.

Recommended Range: 1.6 to 2.4 grams per kilogram of body weight.
Example: A 75 kg person would need 120 to 180 grams daily.

Protein for Muscle Gain

For muscle growth with resistance training, higher protein intake supports repair and growth.

Recommended Range: 1.6 to 2.2 grams per kilogram of body weight.
Example: A 75 kg individual would aim for 120 to 165 grams daily.

Protein for Endurance Athletes

Endurance athletes need elevated protein for muscle recovery and repair.

Recommended Range: 1.2 to 1.6 grams per kilogram of body weight.
Example: A 75 kg athlete would target 90 to 120 grams daily.

Protein for Older Adults

Older adults need more protein to help counteract sarcopenia, the age-related loss of muscle mass.

Recommended Range: 1.2 to 1.6 grams per kilogram of body weight.
Example: A 75 kg older adult would benefit from 90 to 120 grams daily.

Protein Intake Comparison Table


Goal / Population	Protein per kg of body weight	Example for a 75 kg person	Notes
Sedentary Adult (RDA)	0.8 g	60 g	Minimum to prevent deficiency.
Weight Loss	1.6 to 2.4 g	120 to 180 g	Helps preserve lean mass in deficit.
Muscle Gain	1.6 to 2.2 g	120 to 165 g	Supports hypertrophy.
Endurance Athlete	1.2 to 1.6 g	90 to 120 g	Aids recovery and repair.
Older Adult	1.2 to 1.6 g	90 to 120 g	Mitigates age-related muscle loss.

Spreading Your Protein Intake

Distributing your protein evenly across meals (20-40g each) optimizes muscle protein synthesis and ensures a steady supply of amino acids.

High-Quality Protein Sources

Focus on sources containing all nine essential amino acids.

Animal-Based Protein Sources

Chicken Breast: ~27g per 3 ounces.
Eggs: Complete protein, rich in vitamins.
Salmon: Protein and omega-3s.
Greek Yogurt: Mix of whey and casein.
Cottage Cheese: Rich in casein.

Plant-Based Protein Sources

Lentils and Beans: High in protein and fiber.
Tofu and Tempeh: Complete soy-based proteins.
Quinoa: Complete gluten-free grain.
Nuts and Seeds: Protein and healthy fats.

Conclusion: Finding Your Personalized Protein Target

There's no single formula for everyone. The RDA is a minimum, but your personal needs depend on activity, age, and goals. Use weight-based calculations as a starting point. Consult a registered dietitian for personalized advice, especially with health conditions. A balanced diet of whole foods is essential.

Learn more about protein requirements from the American Heart Association.

Frequently Asked Questions

For a healthy, sedentary adult, the simplest formula is to multiply your body weight in kilograms by 0.8 to get your minimum daily protein requirement in grams.

For muscle gain, multiply your body weight in kilograms by a factor between 1.6 and 2.2. For example, a 75 kg person would need 120-165 grams of protein per day.

Yes, a higher protein intake (1.6-2.4 g/kg body weight) can support weight loss by preserving lean muscle mass during a calorie deficit, promoting satiety, and increasing metabolism.

While baseline RDA is based on body weight and not gender, different average body compositions and activity levels can lead to different average protein needs. Ultimately, the calculation should be based on individual factors, not just gender.

Yes, excessive protein intake can cause digestive discomfort, dehydration, and potentially strain the kidneys, especially in individuals with pre-existing kidney conditions. For most healthy people, up to 2 g/kg is safe.

Yes, it is more effective to distribute protein intake throughout the day across multiple meals (20-40g each) rather than consuming it all in one sitting. This helps optimize muscle protein synthesis.

Many animal proteins are 'complete' (containing all essential amino acids). While some plant proteins are incomplete, combining different plant sources throughout the day, like rice and beans, ensures you get all necessary amino acids.