Protein Intake Calculator

How Much Protein Do You Need?

The answer depends on three things: your bodyweight, how hard you train, and your goal. The RDA of 0.8g/kg is the minimum to avoid deficiency — not the optimal amount for anyone who lifts.

For muscle growth, the research converges on 1.6-2.2g per kg bodyweight per day. A landmark meta-analysis by Morton et al. (2018) pooled 49 studies with 1,863 participants and found that 1.6g/kg maximized gains in lean mass. Going higher showed diminishing returns but no harm.

Why Activity Level Matters

Exercise increases protein turnover — your muscles break down during training and rebuild during recovery. More training volume means more muscle protein breakdown, which means more dietary protein is needed to achieve net muscle growth.

• Sedentary: 0.8-1.2g/kg covers basic maintenance. Even non-exercisers benefit from slightly more than the RDA for bone health and satiety.
• Light training (1-2x/week): 1.0-1.8g/kg. Enough to support recovery and modest gains.
• Moderate training (3-4x/week): 1.2-2.0g/kg. The sweet spot for most recreational lifters.
• Heavy training (5-6x/week): 1.4-2.2g/kg. Required for recovery from high-volume programs like PPL or Upper/Lower splits.
• Athlete/2x daily: 1.6-2.8g/kg. The ISSN position stand (Jager et al., 2017) recommends 1.4-2.0g/kg as a baseline for exercising individuals, with up to 2.8g/kg during intense phases.

Protein for Fat Loss

During a caloric deficit, protein becomes even more important. Your body looks for energy wherever it can find it — and muscle is an easy target. Higher protein intake shifts the balance toward fat loss and muscle preservation.

Helms et al. (2014) studied lean athletes (under 15% body fat for men) during caloric restriction and recommended 2.3-3.1g/kg of lean body mass — significantly higher than maintenance levels. For practical purposes, 2.0-2.4g/kg of total bodyweight covers most people cutting for physique goals.

The leaner you are, the more important protein becomes during a cut. At 20% body fat, you have a larger fat reserve to draw from. At 12%, your body is more likely to catabolize muscle without adequate protein.

Protein for Muscle Gain

In a caloric surplus, your body is in an anabolic state — it wants to build. Protein requirements are actually slightly lower during a bulk than during a cut because the surplus itself is muscle-sparing.

The Morton et al. (2018) meta-analysis found 1.6g/kg to be the inflection point — above this, additional protein produces marginal gains. For practical purposes, 1.6-2.2g/kg during a bulk is the evidence-based range. Going above 2.2g/kg just reduces the calories available for carbs and fats without meaningful extra muscle growth.

Protein Timing: Per-Meal Distribution

Research by Schoenfeld & Aragon (2018) suggests distributing protein across 3-5 meals per day, with 20-40g per feeding. Each meal triggers a spike in muscle protein synthesis (MPS) that lasts roughly 3-5 hours. Eating every 3-4 hours keeps MPS elevated throughout the day.

The per-meal ceiling depends on meal composition and body size. Macnaughton et al. (2016) found that 40g of whey protein post-workout stimulated significantly more MPS than 20g in resistance-trained men. Larger individuals may benefit from the higher end (40g+) per meal.

• 3 meals: ~40-55g each. Works if you eat large meals. Risk of exceeding single-meal absorption window.
• 4 meals: ~30-45g each. The most common split for lifters. 3 main meals + 1 post-workout shake or snack.
• 5 meals: ~25-35g each. Optimal for MPS if your schedule allows. Common in contest prep.

Complete vs. Incomplete Proteins

Not all protein sources are equal. Complete proteins contain all 9 essential amino acids in adequate amounts. Animal sources (meat, fish, eggs, dairy) are all complete. Plant sources are often incomplete — but combining them (rice + beans, tofu + quinoa) creates a complete amino acid profile.

The key amino acid for muscle building is leucine — the primary trigger for MPS. Animal proteins are naturally high in leucine (2-3g per serving). Plant proteins typically contain less, so vegetarian and vegan athletes may need slightly higher total protein (1.7-2.4g/kg) to hit the same leucine threshold.

Research Summary

• Morton et al. (2018): Meta-analysis of 49 studies. 1.6g/kg is the point of diminishing returns for lean mass gains in trained individuals.
• Jager et al. (2017): ISSN position stand. 1.4-2.0g/kg for exercising individuals, up to 2.8g/kg in some contexts.
• Helms et al. (2014): 2.3-3.1g/kg lean body mass during caloric restriction for lean athletes.
• Schoenfeld & Aragon (2018): 0.4-0.55g/kg per meal across 4+ meals for optimal MPS distribution.
• Macnaughton et al. (2016): 40g post-workout > 20g for MPS in resistance-trained men.
• Devries et al. (2018): No adverse kidney effects from high-protein diets in healthy adults.