Last updated:
Protein Calculator
Calculate daily protein needs based on body weight, activity level, and fitness goals with per-meal breakdown.
Protein Calculator
Free daily protein intake calculator β get personalized protein recommendations based on your weight, activity level, and fitness goals with AI-powered insights.
Enter values above to see results.
About This Calculator
Related Articles
π In-Depth Guide
This calculator is part of a comprehensive guide
Fitness & Exercise Guide: Complete Workout, Calories & Training Reference 2026
Full GuideComplete fitness and exercise guide covering calorie burn by activity (MET values), heart rate training zones, strength training fundamentals, HIIT vs steady-state cardio, VO2 max, 1RM formulas, beginner workout plans, and recovery science. Backed by ACSM, CDC, and WHO guidelines with free fitness calculators.
The Complete BMI Guide 2026: Formula, Charts, Healthy Ranges & Alternatives
The definitive 2026 BMI guide: metric and imperial formulas with worked examples, WHO/CDC adult categories, Asian-adjusted thresholds, children's BMI percentile charts, athlete limitations, disease risk associations, waist-to-height ratio, body fat percentage alternatives, and 10 evidence-based strategies to reach a healthy weight. Includes free BMI, calorie, and body fat calculators.
The 2026 Evidence-Based Weight Loss Guide: Calorie Deficit, TDEE, Macros, GLP-1 Era & The Science of Sustainable Fat Loss
The most comprehensive 2026 weight-loss guide: calorie deficit math (500 kcal/day = 1 lb/week), TDEE & BMR formulas (Mifflin-St Jeor, Katch-McArdle), 0.7β1.0 g/lb protein for muscle retention, NEAT and adaptive thermogenesis, diet breaks, refeeds, the GLP-1 / semaglutide / tirzepatide era, body recomposition vs cutting, and free CDC-aligned calorie deficit, TDEE, BMR, and body fat calculators.
Protein provides 4 kcal/g and is essential for muscle repair, enzyme synthesis, and immune function. The RDA is 0.8 g/kg/day (minimum for sedentary adults). For muscle building, the ISSN recommends 1.6β2.2 g/kg/day; for weight loss, 1.2β1.6 g/kg preserves lean mass in a deficit. Aim for ~2.5β3 g leucine per meal to trigger maximal muscle protein synthesis (MPS) β achievable with ~25β40 g of quality protein. Distribute protein evenly across 4β5 meals. In healthy individuals, intakes up to 3 g/kg/day are safe.
π₯© Protein Calculator β Complete Guide
Reviewed by CalculatorApp.me Health Editorial Team Β Β·Β Updated June 2026 Β Β·Β 10 min read
How Protein Requirements Are Determined
Protein requirements are set at levels sufficient to maintain nitrogen balance (nitrogen in = nitrogen out). The RDA of 0.8 g/kg/day is the minimum to prevent deficiency in sedentary adults β not the optimal intake for performance or body composition.
The ISSN (International Society of Sports Nutrition) recommends 1.4β2.0 g/kg/day for physically active individuals and 1.6β2.2 g/kg/day for maximizing muscle protein synthesis (MPS). During a calorie deficit, higher intakes (1.8β2.7 g/kg/day) preserve lean mass.
Protein synthesis is triggered by the leucine threshold (~2.5β3 g leucine per meal, achievable with 25β40 g quality protein). Distributing protein across 4β5 meals maximizes MPS stimulation over 24 hours compared to eating all protein in 1β2 meals.
High-Protein Foods per 100g
- βΈChicken breast (raw): 31g
- βΈTuna (canned in water): 29g
- βΈGreek yogurt (2%): 17g
- βΈEggs (whole): 13g
- βΈCottage cheese: 11g
- βΈLentils (cooked): 9g
- βΈTempeh: 19g
- βΈWhey protein powder: ~75β80g
Protein Targets by Goal
| Goal / Population | g/kg/day | Example (75 kg) | Source |
|---|---|---|---|
| Sedentary adults (minimum) | 0.8 | 60 g/day | Institute of Medicine (DRI) |
| General fitness / active adults | 1.2β1.6 | 90β120 g/day | ACSM / AND / DC |
| Muscle building (bulking) | 1.6β2.2 | 120β165 g/day | ISSN 2017 Position Stand |
| Fat loss (caloric deficit) | 1.8β2.7 | 135β200 g/day | ISSN; preserves lean mass |
| Endurance athletes | 1.4β1.7 | 105β130 g/day | ACSM; repairs muscle damage |
| Older adults (65+) | 1.0β1.2 | 75β90 g/day | PROT-AGE Study Group (2013) |
| Plant-based athletes | 1.8β2.2 | 135β165 g/day | 15β20% higher to compensate for lower digestibility |
Protein Myths vs Facts
Frequently Asked Questions
How much protein should I eat to build muscle?βΊ
Research consistently supports 1.6β2.2 g/kg/day for maximizing muscle protein synthesis in resistance-trained individuals. Beyond 2.2 g/kg, additional benefits plateau. For most people, 2 g/kg is a practical target that's well above the threshold while easy to track.
Does protein intake change on rest days?βΊ
Muscle protein synthesis remains elevated for 24β48 hours post-exercise, so high protein intake on rest days is still beneficial for recovery. You don't need to reduce intake on non-training days β keeping protein consistent simplifies meal planning.
What is BCAA and do I need to supplement?βΊ
Branched-chain amino acids (leucine, isoleucine, valine) are three essential amino acids. BCAA supplements are largely unnecessary if you consume sufficient total protein β any complete protein source already contains adequate BCAAs. BCAA supplements benefit primarily those training fasted.
Which protein powder is best?βΊ
Whey protein (from dairy) has the highest DIAAS (digestibility-corrected amino acid score) and is the most researched. Casein digests slowly (good before bed). Plant-based: pea + rice combination provides a complete amino acid profile. Choice depends on dietary preferences and tolerances, not meaningfully on brand.
How does aging affect protein needs?βΊ
After 50β65, anabolic resistance increases β meaning older adults require more protein per meal to trigger the same MPS response as younger adults. The PROT-AGE consensus recommends 1.0β1.2 g/kg/day at minimum for older adults, and 1.2β1.5 g/kg for those who are active or ill.
What happens if I eat too little protein?βΊ
Insufficient protein leads to muscle protein catabolism (your body breaks down muscle for amino acids), impaired immune function, slower wound healing, loss of lean mass, and fatigue. Athletes in caloric restriction who consume inadequate protein lose disproportionate muscle mass.
Does cooking reduce protein content?βΊ
Cooking does not significantly reduce the total amount of protein (nitrogen content). It can alter amino acid bioavailability slightly β cooking actually improves digestibility by denaturing proteins. Protein values on food labels are for raw weight; cooked meat loses water weight, making protein % per gram higher.
Is protein from food the same as from supplements?βΊ
Functionally, yes β the amino acids are identical. Food-derived protein also provides micronutrients, satiety-enhancing fiber (in plants), and other bioactive compounds. Protein powder is convenient for hitting targets but should not replace whole food protein sources for primary intake.
References & Further Reading
- β’ Stokes T et al. β Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training, Nutrients 2018;10(2):180
- β’ Morton RW et al. β A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass, Br J Sports Med 2018;52(6):376-384
- β’ JΓ€ger R et al. β International Society of Sports Nutrition Position Stand: Protein and Exercise, JISSN 2017;14:20
- β’ Bauer J et al. β Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People (PROT-AGE Study Group), JAMDA 2013;14(8):542-559
Related Calculators
Explore All Health & Fitness Calculators
Nutrition, body composition, strength, and wellness tools β all free.
Reviewed by CalculatorApp.me Health Team
Protein Calculator β Complete Guide
Daily protein requirements, optimal intake by goal, protein timing, amino acid science, and food sources.
0.8 g/kg
RDA minimum
1.6-2.2
g/kg for muscle gain
20-30g
Per-meal target
20-35%
Thermic effect
What Is Protein & Why It Matters
Protein is a macronutrient composed of amino acids β the building blocks of muscle, bone, skin, enzymes, and hormones. Of the 20 amino acids, 9 are essential (must come from food): histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Protein is critical for muscle protein synthesis (building/repairing muscle), immune function, enzyme production, hormone regulation, and satiety. It has the highest thermic effect of food (TEF) β your body uses 20-35% of protein calories just to digest it, compared to 5-15% for carbs and 0-5% for fat.
The RDA of 0.8 g/kg body weight is the minimum to prevent deficiency β not the optimal amount. Research consistently shows higher intakes (1.2-2.2 g/kg) benefit muscle retention during weight loss, muscle building, bone health, and appetite control.
Protein Intake Formulas
Daily Protein = Body Weight (kg) Γ Target (g/kg) Targets by goal: Sedentary adult: 0.8 g/kg Active adult: 1.2-1.4 g/kg Endurance athlete: 1.2-1.6 g/kg Strength/muscle gain: 1.6-2.2 g/kg Weight loss (preserve muscle): 1.2-1.6 g/kg Elderly (60+): 1.0-1.2 g/kg Example (80 kg, muscle gain): 80 Γ 1.8 = 144g protein/day = 576 calories from protein
Use lean body mass instead of total weight if obese β otherwise protein targets become unrealistically high.
Daily Protein = Lean Mass (kg) Γ 2.2-3.1 g/kg Lean Mass = Weight Γ (1 β Body Fat %) Example (80 kg, 20% body fat): Lean mass = 80 Γ 0.80 = 64 kg Protein = 64 Γ 2.5 = 160g/day This method is more accurate for: β’ Overweight individuals β’ Very lean individuals β’ Bodybuilders/athletes
Using lean mass normalizes protein targets across different body compositions β equally useful for all body types.
Optimal per-meal dose: 0.4-0.55 g/kg Example (80 kg, 160g/day target): 4 meals Γ 40g = 160g β 3 meals Γ 53g = 160g β Muscle Protein Synthesis (MPS): Threshold: ~20g high-quality protein Ceiling: ~40g per meal Leucine trigger: 2.5-3g per meal High-leucine foods per 30g protein: Whey protein: 3.4g leucine Chicken breast: 2.4g leucine Eggs (5 large): 2.5g leucine Greek yogurt: 1.8g leucine
MPS peaks at 20-40g per meal. The 'muscle full' effect means eating 100g in one meal won't build more muscle than 40g.
Higher protein preserves muscle during deficit: Study (Mettler et al., 2010): Group 1: 1.0 g/kg β lost 1.6 kg muscle Group 2: 2.3 g/kg β lost 0.3 kg muscle Both groups: same calorie deficit! Recommendation during cut: Mild deficit (250 cal): 1.2-1.6 g/kg Moderate deficit (500): 1.6-2.0 g/kg Aggressive deficit (750+): 2.0-2.4 g/kg The leaner you are, the more protein you need to preserve muscle
Higher protein during calorie restriction is the #1 strategy for preserving lean mass. It also increases satiety, reducing hunger.
Top Protein Sources Comparison
| Food | Serving | Protein (g) | Calories | PDCAAS | Leucine (g) |
|---|---|---|---|---|---|
| Chicken breast | 100g | 31g | 165 | 1.00 | 2.4 |
| Whey protein isolate | 1 scoop (30g) | 25g | 110 | 1.00 | 2.7 |
| Eggs | 3 large | 18g | 210 | 1.00 | 1.5 |
| Greek yogurt | 200g | 20g | 130 | 1.00 | 1.6 |
| Salmon | 100g | 25g | 208 | 1.00 | 1.8 |
| Tofu (firm) | 150g | 15g | 130 | 0.56 | 1.1 |
| Lentils | 1 cup cooked | 18g | 230 | 0.52 | 1.3 |
| Almonds | 30g | 6g | 170 | 0.40 | 0.5 |
History of Protein Science
Protein Named by Mulder
Dutch chemist Gerardus Johannes Mulder, at the suggestion of JΓΆns Jacob Berzelius, coined the term 'protein' from the Greek 'proteios' (primary/first). Berzelius wrote: 'The name protein that I propose seems to me very appropriate because this substance appears to be the primitive or principal substance of animal nutrition.'
Amino Acids Discovered
Emil Fischer and Franz Hofmeister independently proposed the peptide bond theory β that proteins are chains of amino acids linked by peptide bonds. Fischer went on to synthesize the first true peptide in 1901 and won the Nobel Prize in 1902.
First RDA Established
The first US Recommended Dietary Allowances (RDAs) were published, including 70g protein/day for men. This was set during WWII to ensure military and civilian nutritional adequacy during rationing.
Protein Quality Scoring (PER β PDCAAS)
The Protein Efficiency Ratio (PER) was replaced by PDCAAS (Protein Digestibility Corrected Amino Acid Score) as the standard for protein quality. PDCAAS scores range from 0-1.0, with animal proteins scoring 1.0 and most plant proteins 0.4-0.7.
Leucine MPS Threshold Discovered
Research by Layman et al. identified leucine as the key amino acid triggering muscle protein synthesis. The threshold dose (~2.5g leucine per meal, found in ~25-30g quality protein) established the modern per-meal protein recommendation.
ISSN Position Stand β Higher Protein
The International Society of Sports Nutrition published their position: athletes and exercisers need 1.4-2.0 g/kg/day protein β nearly 2-3Γ the RDA. For muscle gain during resistance training, 1.6-2.2 g/kg was optimal.
Key Research & Data
British Journal of Sports Medicine
Protein & Muscle Gain Meta-Analysis (2018)
Meta-analysis of 49 studies (1,863 participants): protein supplementation significantly increased muscle mass and strength gains during resistance training. Optimal intake: 1.6 g/kg/day. Benefits plateaued above 1.62 g/kg/day.
American Journal of Clinical Nutrition
Protein Distribution & MPS (Mamerow et al.)
Evenly distributing protein across 3 meals (30g each) stimulated 25% more 24-hour muscle protein synthesis than skewing intake to dinner (10g/15g/65g), despite identical total protein intake.
Journal of the Academy of Nutrition
Protein During Weight Loss (Mettler, 2010)
Athletes in caloric deficit who consumed 2.3 g/kg protein preserved significantly more lean mass than those consuming 1.0 g/kg. The high-protein group lost 1.3 kg less muscle β despite identical calorie deficits.
Annals of Internal Medicine
Protein & Kidney Health in Healthy Adults
A systematic review found no evidence that high protein intake (up to 2.2 g/kg) damages kidneys in healthy adults. The myth originated from clinical guidelines for people with existing kidney disease β not healthy individuals.
Protein Myths vs. Facts
High protein intake damages your kidneys.
No evidence supports this in healthy adults. A comprehensive review found protein up to 2.2 g/kg is safe for healthy kidneys. The restriction applies only to people with pre-existing kidney disease. Hydrate well and you're fine.
You can only absorb 30g of protein per meal.
Your body can digest and absorb virtually unlimited protein. The '30g limit' refers to the muscle protein synthesis ceiling β MPS maxes out at ~40g per meal. Excess protein is used for other functions (enzymes, hormones, energy).
Plant protein is inferior to animal protein.
Individual plant proteins may lack some amino acids, but combining sources (rice + beans, for example) provides complete amino acid profiles. PDCAAS of soy = 1.0 (equal to animal protein). Plant-based athletes can thrive with proper planning.
You need protein immediately after a workout.
The 'anabolic window' is wider than once thought β 4-6 hours, not 30 minutes. Total daily protein intake matters far more than timing. That said, a protein-rich meal within 2 hours post-workout is a good practice.
Frequently Asked Questions
How much protein do I need per day?βΌ
Is whey or casein protein better?βΌ
Can I get enough protein on a vegan diet?βΌ
Does cooking affect protein quality?βΌ
What is PDCAAS?βΌ
Should I take BCAAs or EAAs?βΌ
Does protein help with weight loss?βΌ
How much protein is too much?βΌ
Is protein timing important?βΌ
What about protein for older adults?βΌ
Does excess protein turn into fat?βΌ
What is the anabolic window?βΌ
References
- Morton et al. β Protein & Resistance Training Meta-Analysis (2018)
- Mamerow et al. β Protein Distribution & MPS (AJCN, 2014)
- ISSN Position Stand β Protein and Exercise (2017)
- Mettler et al. β Protein During Energy Restriction (2010)
- Layman β Leucine & Muscle Protein Synthesis
- Examine.com β Protein Evidence Summary
Related Calculators
Explore All Health Calculators
Optimize your nutrition with science-backed protein, calorie, and fitness tools β CalculatorApp.me.
Browse Health Calculators β