Frequently Asked Questions

Daily protein needs vary based on your body weight, activity level, and goals. Sedentary adults need approximately 0.8g per kilogram of body weight (0.4 g/lb). Active individuals who exercise regularly need 1.2–1.6 g/kg (0.5–0.7 g/lb). Those focused on building muscle or losing fat while preserving lean mass should aim for 1.6–2.4 g/kg (0.7–1.1 g/lb) per day, according to the International Society of Sports Nutrition (ISSN).

Protein is a macronutrient made up of amino acids — the building blocks your body uses to build and repair muscle tissue, produce enzymes and hormones, support immune function, and maintain healthy skin, hair, and nails. It is the only macronutrient that directly builds lean muscle mass, making it essential for anyone who exercises.

Insufficient protein intake can lead to muscle loss (sarcopenia), slower recovery from exercise, weakened immune function, increased hunger and cravings, brittle hair and nails, fatigue, and difficulty maintaining or building muscle. Over time, protein deficiency impairs your body's ability to repair tissue and maintain lean mass.

For healthy adults with normal kidney function, research shows that protein intakes up to 2.2–3.0 g/kg/day (1.0–1.4 g/lb/day) are safe and do not cause kidney damage. A 2016 study published in the Journal of the International Society of Sports Nutrition found no adverse effects in resistance-trained individuals consuming up to 3.3 g/kg/day (1.5 g/lb/day) for over a year. However, individuals with pre-existing kidney disease should consult their physician.

The recommended protein intake per kilogram of body weight is similar for both men and women. The absolute amount (in grams) differs because men typically weigh more, but the g/kg (or g/lb) recommendation remains the same. Both sexes benefit equally from adequate protein for muscle maintenance, recovery, and body composition goals.

Our calculator uses evidence-based protein recommendations from the ISSN, ACSM, and peer-reviewed meta-analyses. It uses your age, weight, activity level, resistance training frequency, and fitness goal to estimate a personalized protein range. Optional height and gender details do not change the result. The algorithm adjusts base recommendations for training volume and age-related protein needs.

Our recommendations are derived from four primary sources: (1) ISSN Position Stand on Protein and Exercise (2017), (2) ACSM/AND/DC Joint Position on Nutrition and Athletic Performance (2016), (3) British Journal of Sports Medicine systematic review and meta-analysis on dietary protein for resistance training (2018), and (4) Journal of the Academy of Nutrition and Dietetics evidence-based recommendations for active adults (2016).

Yes, completely free. There is no signup required, no email capture, no premium tier, and no hidden costs. The calculator runs entirely in your browser — we don't even store your inputs on our servers.

Our calculator provides evidence-based estimates that align with the latest sports nutrition research. It gives you a recommended range (minimum, target, and maximum) rather than a single number because individual needs vary. For the most precise recommendations, especially if you have health conditions, consult a registered dietitian who can perform a full nutritional assessment.

Resistance training creates micro-damage in muscle fibers that requires protein for repair and growth. More training days per week means more recovery demand. Research shows that individuals training 5–7 days per week need more protein than those training 1–2 days, even at the same overall activity level. Our calculator adjusts your recommendation accordingly.

The ISSN recommends 1.6–2.2g of protein per kilogram of body weight per day (0.7–1.0 g/lb/day) for muscle building. A 2018 meta-analysis in the British Journal of Sports Medicine confirmed that protein intakes above 1.6 g/kg/day (0.7 g/lb/day) result in greater gains in lean mass when combined with resistance training. For most people, 2.0 g/kg (0.9 g/lb) is a good target for maximizing muscle protein synthesis.

During a calorie deficit (fat loss phase), protein needs are higher than maintenance — typically 1.8–2.7 g/kg/day (0.8–1.2 g/lb/day). Higher protein intake during weight loss serves three purposes: (1) preserves lean muscle mass that would otherwise be lost, (2) increases satiety so you feel fuller longer, and (3) has a higher thermic effect (your body burns approximately 20–30% of protein calories during digestion, compared to 5–10% for carbs and 0–3% for fats).

Endurance athletes need slightly less protein than strength athletes, but more than sedentary individuals. The ACSM recommends 1.2–1.7 g/kg/day (0.5–0.8 g/lb/day) for endurance athletes compared to 1.6–2.2 g/kg/day (0.7–1.0 g/lb/day) for strength athletes. Endurance training still breaks down muscle tissue and creates oxidation of amino acids for fuel, so adequate protein is essential for recovery and adaptation.

For weight maintenance with regular activity, aim for 1.0–1.6 g/kg/day (0.5–0.7 g/lb/day) depending on your exercise frequency. If you exercise lightly (1–3 days/week), stay toward the lower end. If you're moderately active (3–5 days/week), the middle range (1.2–1.4 g/kg, or 0.5–0.6 g/lb) works well. This maintains muscle mass and supports daily bodily functions without excess.

Yes. Adults over 50 experience "anabolic resistance" — their muscles become less responsive to the muscle-building signal from protein. Research published in the Journal of the American Medical Directors Association recommends that older adults consume 1.0–1.5 g/kg/day (0.5–0.7 g/lb/day), vs. 0.8 g/kg (0.4 g/lb) for younger sedentary adults, to maintain muscle mass, prevent sarcopenia, and support bone health. Those over 65 who are active may need up to 1.6–2.0 g/kg/day (0.7–0.9 g/lb/day).

Research suggests that distributing protein evenly across 3–5 meals throughout the day (20–40g per meal) is more effective for muscle protein synthesis than consuming it all in one or two meals. While the "anabolic window" after exercise is less critical than once thought, consuming 20–40g of protein within a few hours of training can support recovery. Total daily intake matters more than exact timing.

Research indicates that approximately 20–40g of protein per meal maximally stimulates muscle protein synthesis. A 2018 study found that 0.4 g/kg (0.18 g/lb) per meal across 4 meals is optimal. Going beyond 40g in a single meal doesn't waste protein (your body will still use it), but the muscle-building benefit per additional gram diminishes. Our calculator divides your daily target by 4 meals for a practical per-meal goal.

Both are beneficial, and the difference between pre- and post-workout protein is minimal. The most important factor is consuming adequate protein within a few hours on either side of your workout. If you train fasted in the morning, prioritize protein soon after. If you had a meal 2–3 hours before training, you have more flexibility on timing post-workout. A good rule: don't go more than 4–5 hours without protein around your training.

Yes. Research by Snijders et al. (2015) demonstrated that consuming 30–40g of casein protein before sleep increases overnight muscle protein synthesis rates and supports recovery. This is especially beneficial for people who train in the evening or struggle to meet their daily protein target. Slow-digesting proteins like casein, Greek yogurt, or cottage cheese are ideal before bed.

The highest quality protein sources include chicken breast (31g per 100g), eggs (13g per 100g), Greek yogurt (10g per 100g), salmon (25g per 100g), lean beef (26g per 100g), whey protein powder (25g per scoop), lentils (9g per 100g cooked), and tofu (8g per 100g). "Quality" refers to the amino acid profile and digestibility — animal proteins are complete (contain all essential amino acids), while most plant proteins need to be combined for completeness.

Absolutely. Plant-based athletes can meet their protein needs through strategic food combining. Key sources include: tofu, tempeh, seitan, legumes (lentils, chickpeas, black beans), quinoa, soy milk, pea protein powder, nuts, and seeds. The key is variety — combining different plant proteins throughout the day ensures you get all essential amino acids. Plant-based individuals may benefit from aiming slightly higher (10–15% more) to account for lower digestibility.

Protein supplements are not necessary if you can meet your daily target through whole foods. However, they are convenient, cost-effective per gram of protein, and useful when whole food meals aren't practical (post-workout, travel, busy schedules). Whey protein is the most researched supplement and has a high leucine content that strongly stimulates muscle protein synthesis. It's a tool, not a requirement.