SamCalculator

Protein Calculator

Calculate your ideal daily protein intake for muscle growth, fat loss, performance, and overall health.

Last updated: May 15, 2026

Medical disclaimer: Estimates only. Not a substitute for advice from a registered dietitian or physician. People with kidney disease, liver disease, or who are pregnant must consult a clinician before changing protein intake.

years

Recommended range: 18–80

cm
kg

Suggested for this goal: 1.8 g/kg

What Is Protein?

Protein is one of the three macronutrients (alongside carbohydrates and fat) and the only one your body can't store in significant amounts long-term. Each gram delivers 4 kcal. Protein is built from 20 amino acids, nine of which are essential — your body can't produce them, so they must come from food.

Protein is the structural material for muscle, skin, hair, nails, hormones, antibodies, and almost every enzyme in your body. Unlike carbs and fat, protein doesn't fuel exercise efficiently — its primary job is repair, growth, and metabolic signaling.

Complete proteins

All 9 essential amino acids in good ratios. Animal foods, soy, quinoa, buckwheat.

Incomplete proteins

Missing one or more EAAs. Most plant foods. Combine (rice + beans) for a complete profile.

Leucine

The single amino acid that triggers muscle protein synthesis. Need ~2–3 g per meal.

Why Protein Matters

Of the three macronutrients, protein has the strongest evidence base for impacting body composition, satiety, strength, and long-term health. Key effects:

  • • Muscle protein synthesis: protein (specifically leucine) signals your muscles to grow and repair after training.
  • • Satiety: the most filling macro per calorie — controlled trials show protein at 25%+ of calories suppresses hunger more than carbs or fat.
  • • Thermic effect of food (TEF): protein burns 20–30% of its own calories during digestion vs. 5–10% for carbs and 0–3% for fat.
  • • Lean mass preservation: high protein in a calorie deficit protects muscle (Longland 2016, Helms 2014).
  • • Bone health: contrary to old myths, higher protein intake correlates with better bone density (PROT-AGE consensus, 2013).
  • • Healthy aging: adults 65+ need 30–50% more protein than the RDA to fight sarcopenia (Bauer et al. 2013).

Protein for Muscle Growth

The International Society of Sports Nutrition (ISSN, 2017) recommends 1.4–2.0 g per kg body weight for active adults pursuing muscle growth. The American College of Sports Medicine and Academy of Nutrition and Dietetics agree.

The muscle-growth starting point

  • • Protein: 1.6–2.0 g/kg body weight (≈ 0.7–0.9 g/lb)
  • • Per meal: 0.4 g/kg per meal, 3–5 meals/day
  • • Calories: TDEE + 250–500 kcal/day
  • • Training: progressive resistance training 3–5×/week
  • • Timing: spread protein across the day; the "anabolic window" is much wider than 30 min

Going significantly above 2.0 g/kg doesn't add measurable hypertrophy in trained lifters but is harmless in healthy adults (Morton et al. 2018 meta-analysis). The benefit of "high" protein during a bulk is mostly satiety and meal structure, not extra growth.

Protein for Fat Loss

During a calorie deficit, protein becomes your single most important macro. It does two critical jobs: it preserves muscle mass that would otherwise be burned for energy, and it controls hunger by triggering satiety hormones like PYY and GLP-1.

The fat-loss protein starting point

  • • Protein: 1.8–2.4 g/kg (the cut-phase range)
  • • Calories: TDEE − 500 kcal/day (≈ 0.5 kg / 1 lb per week)
  • • Resistance training: non-negotiable for muscle retention
  • • Adjust: bump protein toward 2.4 g/kg in aggressive deficits or contest prep

Landmark trial: Longland et al. (2016) put dieters in a steep deficit with 2.4 g/kg vs. 1.2 g/kg protein. The high-protein group gained 1.2 kg of lean mass while losing fat; the low-protein group only maintained lean mass. Higher protein in a deficit doesn't slow fat loss — it improves body composition.

Best Protein Sources

Aim for a mix of complete proteins and use plant proteins liberally — they're rich in fiber and phytonutrients animal proteins lack.

SourceProtein / 100 gkcal / 100 gType
Chicken breast (cooked)31 g165Animal
Whey protein isolate80–90 g370Dairy
Salmon (cooked)25 g208Animal
Beef (lean, cooked)26 g217Animal
Greek yogurt (plain, low fat)10 g59Dairy
Paneer (Indian cottage cheese)18 g265Dairy
Cottage cheese (low fat)11 g72Dairy
Eggs (whole)13 g155Animal
Tofu (firm)12 g144Plant
Tempeh19 g192Plant
Soy chunks (dry)52 g345Plant
Lentils (cooked)9 g116Plant
Chickpeas (cooked)9 g164Plant
Edamame (cooked)11 g121Plant
Quinoa (cooked)4 g120Plant

Source: USDA FoodData Central. Values for cooked/dry forms vary slightly by preparation.

Vegetarian vs Animal Protein

Animal proteins (chicken, eggs, fish, dairy) are complete proteins — they contain all nine essential amino acids in muscle-building ratios. Most plant proteins are incomplete, missing one or more EAAs. But this is solved easily with variety.

Vegetarian / vegan tips

  • • Lean on soy: tofu, tempeh, soy chunks, soy milk are complete
  • • Combine grains + legumes (rice + dal, hummus + pita)
  • • Add ~10–15% to your protein target (lower digestibility, DIAAS)
  • • Whey isolate or plant blends (pea + rice) close gaps
  • • Spread protein across 4–5 meals to hit leucine threshold

Animal protein tips

  • • Prioritize lean cuts: chicken breast, fish, lean beef, eggs
  • • Greek yogurt and cottage cheese deliver slow-release casein
  • • Whey is the most studied post-workout protein
  • • 1 serving (100–150 g cooked meat) ≈ 25–35 g protein
  • • Don't skimp on plants — fiber and micronutrients matter

Bottom line: a well-planned vegetarian or vegan diet supports muscle gain and fat loss just as effectively as an omnivorous one (Pinckaers et al. 2024). Most plant-based athletes simply target the upper end of their range (2.0–2.4 g/kg).

Protein g/kg by Goal — Quick Reference

GoalProtein g/kgFor an 80 kg adult
Sedentary maintenance (US RDA)0.8–1.064–80 g
General fitness1.2–1.696–128 g
Fat loss (preserve muscle)1.6–2.2128–176 g
Muscle gain / hypertrophy1.6–2.4128–192 g
Strength athletes / lifters1.6–2.2128–176 g
Endurance athletes1.2–1.696–128 g
Physique / contest prep2.2–3.1176–248 g
Healthy aging (65+)1.2–1.696–128 g

Sources: USDA DRI; ISSN Position Stand (2017); AND/DC/ACSM Joint Position (2016); PROT-AGE Consensus (Bauer et al. 2013); Helms et al. (2014).

Frequently Asked Questions

For most active adults the ISSN recommends 1.4–2.0 g of protein per kg of body weight per day. Sedentary adults can sit at the US RDA floor of 0.8 g/kg, but typically plateau in body composition. During fat loss or intense training, push the upper end (1.6–2.2 g/kg) to preserve muscle. An 80 kg / 176 lb adult typically needs 130–180 g/day. The calculator above gives a personalized target.

Aim for 1.6–2.0 g of protein per kg of body weight per day, split across 3–5 meals of 0.3–0.4 g/kg each. For an 80 kg lifter, that's 130–160 g/day, or about 35–40 g of protein per meal. A 2018 meta-analysis (Morton et al., Br J Sports Med) found no additional hypertrophy above ~1.6 g/kg in trained adults, but the upper end may help with satiety and meal structure.

1.6–2.4 g/kg of body weight is the cut-phase range. Higher protein in a deficit protects muscle mass that would otherwise be burned for energy, controls hunger, and burns more calories through the thermic effect of food. Landmark trial: Longland 2016 found 2.4 g/kg in a steep deficit produced 1.2 kg of lean mass gain while losing fat — vs. 1.2 g/kg, which only maintained muscle.

For healthy adults, no. Intakes up to 3.0–3.5 g/kg have been studied in trained populations with no adverse effects on kidney function, bone density, or hydration (Antonio et al., 2014–2016). The 'protein damages kidneys' claim applies only to people with existing chronic kidney disease — healthy kidneys handle high protein loads fine. People with CKD, liver disease, or certain metabolic disorders should consult a clinician before raising protein.

Soy products top the list: tofu, tempeh, soy chunks (52 g per 100 g dry!), edamame, and soy milk are complete proteins. Other strong sources: Greek yogurt, paneer, cottage cheese, eggs, whey or plant-based protein powder, lentils, chickpeas, quinoa, and nuts and seeds. Vegetarians should target the upper end of their range (2.0–2.4 g/kg) since plant proteins have slightly lower digestibility (DIAAS).

Less than the supplement industry suggests. The total daily protein intake is the biggest driver. The 'anabolic window' is actually 4–6 hours wide, not 30 minutes. What does matter: hitting your daily total, splitting protein across 3–5 evenly-spaced meals of ≥ 0.4 g/kg each, and including a protein source before bed (especially slow-release casein) if you've trained hard that day.

Aim for 0.4 g/kg body weight per meal — about 30–40 g of protein for most adults — to maximally stimulate muscle protein synthesis (Schoenfeld & Aragon, 2018). Below this, MPS is sub-maximally triggered. Above it, the extra protein is still useful but adds nothing for muscle building in that meal. Spread across 3–5 meals for the best 24-hour anabolic response.

Protein powder isn't necessary — it's just convenient. Whey isolate, casein, and plant blends (pea + rice) deliver 20–30 g of high-quality protein per scoop in seconds, with minimal calories. They're useful for people who struggle to hit their target from whole foods, or who want a quick post-workout meal. Whole-food protein and powder are equally effective for muscle gain when calorie and total protein are matched.

Only if it pushes you into a calorie surplus. Protein has 4 kcal/g — same as carbs. Its high satiety and thermic effect actually make it easier to stay in a deficit. In studies where total calories were matched, higher-protein diets produced more fat loss and better body composition than lower-protein diets. Protein is not fat-storing — overeating in total is.

The AND/DC/ACSM joint position recommends 1.2–1.6 g/kg for endurance athletes — slightly lower than strength athletes because their primary fuel is carbs, not protein. Ultra-endurance and multi-day stage athletes lean toward 1.4–1.7 g/kg. Protein still matters for endurance — it supports mitochondrial biogenesis, immune function, and recovery between long sessions.

Older adults need MORE protein than the RDA, not less. The PROT-AGE consensus (Bauer et al. 2013) recommends 1.0–1.2 g/kg for healthy seniors and 1.2–1.5 g/kg for those with acute or chronic disease — 30–60% above the 0.8 g/kg RDA. Higher protein, combined with resistance training, fights sarcopenia (age-related muscle loss), preserves bone density, and supports immune function.

It's a useful rule of thumb that lands at 2.2 g/kg — the upper end of evidence-based ranges. It overshoots what most controlled trials show as maximally useful for muscle gain (≈1.6 g/kg) but is harmless and convenient for trained lifters. For most adults, 0.7–0.9 g per pound (1.6–2.0 g/kg) is the evidence-based sweet spot.

Yes — and at the same daily target. Muscle repair, hormone production, immune function, and metabolic signaling happen 24/7, not just on training days. Some lifters slightly drop calories on rest days but keep protein constant. Cutting protein on rest days slows recovery and progress.

Yes, when matched for total protein and leucine content. A 2024 meta-analysis (Pinckaers et al.) found plant-based diets produce equivalent strength and lean-mass gains as omnivorous diets — provided plant protein intake is slightly higher (2.0–2.4 g/kg) and includes high-leucine sources like soy. The key is variety and adequacy, not animal vs. plant.

The Mifflin-St Jeor BMR equation underlying this tool is accurate within ±10% for most healthy adults. Protein recommendations are based on validated ranges from the ISSN, AND/DC/ACSM, and PROT-AGE consensus statements. Real-world accuracy depends on honest activity reporting and consistent food tracking. Treat the output as a starting point; adjust by 10–20 g after 2–4 weeks based on real progress, hunger, and recovery.

Methodology, Authors & Review

Authored by

SamCalculator Editorial Team

A team of writers and analysts producing evidence-based health, finance, and fitness tools, anchored to peer-reviewed research and official US public-health guidance.

Editorial standards

Cross-checked, not clinical advice

Formulas, ranges, and recommendations on this page are cross-checked against the USDA DRI, the ISSN Position Stand on Protein and Exercise, the AND/DC/ACSM joint athletic nutrition consensus, and the PROT-AGE consensus on protein needs in older adults. SamCalculator does not employ licensed clinicians; this page is general education, not medical or dietetic advice.

Methodology

BMR is calculated using the Mifflin-St Jeor equation (1990) — the most accurate formula per the Academy of Nutrition and Dietetics. Katch-McArdle is offered when body fat % is known. TDEE = BMR × activity multiplier, with 6 PAL bands ranging from 1.2 (sedentary) to 2.0 (athlete). Protein intake is calculated as g/kg of body weight, with five evidence-based strategies (1.2, 1.8, 2.0, 2.2, 2.4 g/kg) covering general fitness, muscle gain, fat loss, athletes, and contest prep. The "goal" dropdown applies an additional bias toward the strategy that best fits the chosen objective. Per-meal protein splits the daily total evenly across 2–6 meals, with research-backed guidance of ≥ 0.4 g/kg per meal for optimal muscle protein synthesis (Schoenfeld & Aragon, 2018).

Last reviewed: May 15, 2026

Scientific References

  1. USDA & HHS — Dietary Guidelines for Americans, 2020–2025
  2. IOM — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
  3. Jäger R, et al. (2017). ISSN Position Stand: Protein and Exercise. JISSN.
  4. Thomas DT, Erdman KA, Burke LM. (2016). AND/DC/ACSM Position: Nutrition and Athletic Performance.
  5. Bauer J, et al. (2013). Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People: PROT-AGE.
  6. Longland TM, et al. (2016). Higher compared with lower dietary protein during an energy deficit. Am J Clin Nutr.
  7. Helms ER, Aragon AA, Fitschen PJ. (2014). Evidence-based recommendations for natural bodybuilding contest preparation. JISSN.
  8. Morton RW, et al. (2018). Systematic review and meta-analysis of protein supplementation on resistance-training-induced gains. Br J Sports Med.
  9. Schoenfeld BJ, Aragon AA. (2018). How much protein can the body use in a single meal for muscle-building? JISSN.
  10. Mifflin MD, St Jeor ST, et al. (1990). A new predictive equation for resting energy expenditure. Am J Clin Nutr.

Health disclaimer: This protein calculator is for general informational and educational purposes only and is not a substitute for personalized advice from a registered dietitian (RD/RDN), licensed nutritionist, or board-certified physician. People with chronic kidney disease, liver disease, certain metabolic disorders, or who are pregnant or breastfeeding must consult a clinician before significantly raising protein intake. Protein recommendations on this page assume otherwise healthy adults.

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