Protein Intake Calculator
Calculate your daily protein needs based on your weight, fitness goals, and activity level. Uses lean body mass when body fat percentage is provided for greater accuracy. Supports muscle gain, weight loss, body recomposition, and GLP-1 medication support. 100% private.
How Protein Intake Calculator Works
Calculate your daily protein needs based on weight, goals, and activity level. — supports muscle gain, weight loss, maintenance. Enter your values into the form above and the calculator processes them instantly in your browser — no data is sent to any server.
How Much Protein Do You Really Need?
Protein is the most important macronutrient for building and repairing muscle tissue, supporting immune function, and maintaining healthy bones and organs. The recommended dietary allowance (RDA) of 0.8g per kilogram of body weight is the minimum to prevent deficiency, not the optimal amount for active individuals. Research consistently shows that people who exercise regularly, want to lose fat while preserving muscle, or are over 50 benefit from significantly more protein than the RDA suggests.
This protein intake calculator uses evidence-based multipliers that factor in your body weight (or lean body mass if you provide body fat percentage), your activity level, your fitness goal, and your age. The result is a personalized daily protein target tailored to your situation.
Protein Needs by Goal and Activity Level
Weight loss: 1.2-1.6g per kg of body weight. Higher protein during a caloric deficit helps preserve lean muscle mass, keeps you feeling full longer, and increases the thermic effect of food (your body burns more calories digesting protein than carbs or fat). Muscle gain: 1.6-2.2g per kg. This range is supported by a 2018 meta-analysis in the British Journal of Sports Medicine. Maintenance: 0.8-1.2g per kg depending on activity level. Body recomposition: 1.6-2.0g per kg, as you need adequate protein to build muscle while losing fat simultaneously. Athletes: 1.4-2.0g per kg, with endurance athletes at the lower end and strength athletes at the higher end.
Best Protein Sources by Diet Type
Getting enough protein is achievable on any diet. Omnivores have the widest selection: chicken breast (31g per 100g), eggs (6g each), Greek yogurt (10g per 100g), salmon (25g per 100g), and lean beef (26g per 100g). Vegetarians can rely on eggs, Greek yogurt, cottage cheese, tofu (17g per 100g), and lentils (9g per 100g cooked). Vegans should combine sources like tofu, tempeh (19g per 100g), lentils, chickpeas, quinoa, and edamame. Pescatarians benefit from fish, shrimp, eggs, and dairy alongside plant sources. Regardless of diet, aim for 25-40g of protein per meal to maximize muscle protein synthesis.
Protein Timing and Distribution
Research shows that distributing protein evenly across meals (rather than eating most at dinner) is more effective for muscle protein synthesis. Aim for 3-4 protein-rich meals spaced 3-5 hours apart, with each containing at least 25-40g of protein. A post-workout meal or shake within 2 hours of training can enhance recovery, though total daily intake matters more than exact timing. For older adults (50+), this even distribution becomes even more critical, as the muscle protein synthesis response to each meal requires a higher protein threshold.
Protein on GLP-1 Medications
If you are taking GLP-1 receptor agonists like Ozempic, Wegovy, or Mounjaro, protein intake becomes critically important. These medications cause significant weight loss, but up to 40% of weight lost can be muscle mass without adequate protein and resistance training. A target of 1.2-1.6g per kg of body weight, combined with strength training 2-3 times per week, helps preserve lean muscle mass during rapid weight loss. Since appetite is suppressed, prioritize protein-dense foods at every meal to meet your target within a reduced calorie budget.
Frequently Asked Questions
How much protein do I need per day?
It depends on your weight, activity level, age, and goals. The minimum RDA is 0.8g per kg of body weight, but active individuals and those aiming to build muscle or lose fat benefit from 1.2-2.2g per kg. This calculator provides a personalized range based on your inputs.
Should I use total body weight or lean body mass?
If you know your body fat percentage, using lean body mass (total weight minus fat weight) gives a more accurate protein target, especially for individuals with higher body fat. If you do not know your body fat percentage, total body weight works well as a baseline.
Can I eat too much protein?
For healthy individuals with normal kidney function, protein intakes up to 2.2g per kg per day are well-studied and safe. Very high intakes (above 3g/kg) have no proven additional benefit for most people. Those with kidney disease should consult a physician before increasing protein intake.
Why do older adults need more protein?
After age 50, the body becomes less efficient at using dietary protein to build muscle, a condition called anabolic resistance. Research recommends 1.0-1.3g per kg for adults over 50, and 1.2-1.5g per kg for those over 65, to help prevent age-related muscle loss (sarcopenia).
Why is protein important on GLP-1 medications?
GLP-1 receptor agonists like Ozempic, Wegovy, and Mounjaro cause rapid weight loss, but up to 40% of weight lost can be muscle without adequate protein and exercise. Prioritizing 1.2-1.6g of protein per kg of body weight alongside resistance training helps preserve lean muscle mass during treatment.
Is this calculator private?
Yes. All calculations run entirely in your browser. No personal health data is sent to any server. Your inputs are saved locally for convenience and can be cleared at any time.
How should I distribute protein across meals?
Research suggests spreading protein intake evenly across 3-4 meals (25-40g each) maximizes muscle protein synthesis. Eating most of your protein in one meal is less effective than distributing it throughout the day.