Protein Intake Calculator
Determine evidence-based daily protein targets and per-meal amino acid distributions tailored to your body weight, physical activity, and body recomposition goals.
Protein Intake Calculator
Evidence-based daily protein ranges for muscle hypertrophy, fat-loss lean mass preservation, and endurance sports.
Recommended: ~143 g/day
0.73–1 g/lb
Even amino acid distribution
Optimal MPS pulse every 3-4h
Scientific Evidence & Guidelines:
Morton et al. (2018) Meta-Analysis: 1.6–2.2 g/kg optimal for muscle protein synthesis.
Unlike outdated fixed RDA values (0.8 g/kg) intended solely to prevent severe nitrogen deficiency in sedentary populations, contemporary sports nutrition literature establishes that resistance-trained individuals and individuals in caloric deficits require significantly higher amino acid availability to maximize muscle protein synthesis and prevent catabolism.
Clinical Screening Reference & Medical Notice
Calculations provided on HOW WEIGHT are based on published statistical standards (such as WHO, CDC, and peer-reviewed metabolic equations) and are intended for educational and general screening purposes only.
They do not directly measure body fat distribution or visceral adipose tissue, nor do they replace personalized clinical diagnostic evaluation by a licensed healthcare provider. Learn more about our clinical methodology & disclaimers →
The Science of Muscle Protein Synthesis (MPS) vs. Catabolism
Skeletal muscle mass exists in a continuous dynamic turnover between Muscle Protein Synthesis (MPS) and Muscle Protein Breakdown (MPB). For muscle hypertrophy or preservation to occur, Net Protein Balance (NPB = MPS - MPB) must remain positive. In 2018, Morton and colleagues published a landmark British Journal of Sports Medicine meta-analysis of 49 randomized controlled trials with 1,863 participants, confirming that protein supplementation up to 1.62 g/kg (with an upper 95% confidence interval of 2.2 g/kg) significantly augments resistance training-induced gains in muscle mass and strength.
| Nutritional Objective | Intake (g / kg body weight) | Intake (g / lb body weight) | Primary Physiological Mechanism | Key Literature Citation |
|---|---|---|---|---|
| Sedentary Maintenance | 0.8 – 1.0 g/kg | 0.36 – 0.45 g/lb | Prevents negative nitrogen balance in non-lifters | Institute of Medicine (RDA standard) |
| Endurance Athletes | 1.2 – 1.6 g/kg | 0.55 – 0.73 g/lb | Compensates for amino acid oxidation during long runs | ACSM / Dietitians of Canada Position Stand |
| Muscle Hypertrophy | 1.6 – 2.2 g/kg | 0.73 – 1.00 g/lb | Maximizes myofibrillar MPS rate post-resistance exercise | Morton et al. (Br J Sports Med 2018) |
| Fat Loss & Deficit | 1.8 – 2.4 g/kg | 0.82 – 1.10 g/lb | Attenuates muscle catabolism and boosts satiety via peptide YY | Helms et al. (JISSN 2014) |
Worked Protein Distribution Example
Suppose an 80.0 kg (176.4 lb) lifter is aiming for muscular hypertrophy (target: 2.0 g/kg):
- Daily Total Target: 80.0 kg × 2.0 g/kg = 160 grams of protein per day.
- Energy equivalent: 160 g × 4 kcal/g = 640 kcal from dietary protein.
- Distributed across 4 meals: 160 ÷ 4 = 40 grams of complete protein per meal.
- Optimal Timing: Consuming 40g every 3.5 to 4 hours ensures continuous stimulation of ribosomal muscle protein synthesis.
Frequently Asked Questions
How much protein do I actually need per day?
While the basic RDA of 0.8 g/kg prevents severe deficiency in sedentary adults, extensive sports nutrition research confirms that active individuals and athletes require 1.4 to 2.2 grams per kilogram of body weight (0.65 to 1.0 g/lb). Individuals in a caloric deficit benefit from 1.8 to 2.4 g/kg to protect muscle tissue.
Why does protein requirement increase during a calorie deficit?
When total caloric energy is restricted, the body increases hepatic gluconeogenesis—the conversion of amino acids into glucose for fuel. Consuming elevated protein (1.8–2.4 g/kg) ensures sufficient circulating amino acids to preserve skeletal muscle myofibrillar proteins from being catabolized.
What is the "leucine trigger" and per-meal protein distribution?
Leucine is the primary branched-chain amino acid that initiates the mTORC1 signaling pathway for Muscle Protein Synthesis (MPS). Reaching the "leucine trigger" requires roughly 2.5 to 3.0 grams of leucine, equivalent to approximately 25 to 40 grams of complete high-quality protein per meal, distributed every 3 to 5 hours.
Can high protein intake harm healthy kidneys?
Comprehensive meta-analyses (including Devries et al., 2018) have evaluated protein intakes up to 2.8 to 3.3 g/kg in healthy individuals with normal renal function and found zero evidence of kidney damage, glomerular filtration degradation, or renal disease initiation. However, individuals with pre-existing chronic kidney disease (CKD) should adhere to medically supervised protein restrictions.
Do plant-based proteins have the same biological value as animal proteins?
Most individual plant proteins have slightly lower concentrations of essential amino acids (particularly leucine, methionine, and lysine) and lower bioavailability. Plant-based athletes can achieve identical muscle protein synthesis by consuming a slightly higher total protein range (~10% more) and combining varied sources (such as legumes with grains).