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Calculated as body weight × — g/kg
How to Use the Protein Calculator
Protein is the building material for muscle, bone, skin and hair, and it is essential for repairing the muscle fibers damaged during training. If you fall short, your muscles will not grow no matter how hard you train. This tool estimates the protein (g) you need per day from your body weight and goal.
How to use this tool
Enter your body weight and select your goal (cut, maintain, or bulk/hypertrophy). A common guideline is about 1.0 g per kg of body weight for general health and 1.6-2.2 g for people who train. The result is a daily total, so spread it across 3-5 meals and snacks.
Reading the result
A per-meal target is also shown. Muscle protein synthesis is maximized by roughly 20-40 g of protein at a time, so splitting intake into smaller, frequent servings is more efficient than one large dose. If you carry more body fat, base the figure on lean body mass to avoid over-estimating.
Tips
Aim to get protein mainly from whole foods such as meat, fish, eggs, soy and dairy, and top up with protein powder when convenient. Check your overall balance with the PFC calculator.
Per-meal dose, and why spreading it out matters
Muscle protein synthesis rises with the amount of protein in a meal, but plateaus somewhere around 20–40 g across multiple studies. Someone needing 150 g a day gets more out of 30–40 g spread over four or five meals than the same total loaded into dinner. Breakfast is the usual weak point: a conventional Japanese breakfast often supplies only about 10 g.
Animal and plant sources are not interchangeable
Protein quality comes down to essential amino acid balance and digestibility. Meat, fish, eggs and dairy score well on both and are rich in leucine, the amino acid that triggers synthesis. Soy is the strongest plant source, while grains and vegetables tend to fall short in one amino acid or another. On a mostly plant-based diet, budget 10–20% more total protein and combine several sources to cover the gaps.
What happens if you overshoot
There is no good evidence that high protein intake damages healthy kidneys. But protein carries calories too — four per gram — so a large excess is stored as body fat like anything else. It also tends to crowd out fibre- and vitamin-rich foods, unbalancing the diet as a whole. Anyone with existing kidney disease should follow their doctor's guidance rather than a general calculator.
Glossary & FAQ
Why is protein necessary for strength training?+
When you strength-train, muscle fibers are slightly damaged, and during the repair and regeneration process your muscles grow larger and stronger (supercompensation). Protein is needed for this repair.
If protein is lacking, it becomes hard to build muscle even with training, and in some cases muscle can be broken down.
What does g/kg (grams per kilogram) mean?+
For example, at "1.6 g/kg" and a body weight of 70 kg:
70kg × 1.6 = 112g is the daily target.Because the required amount changes with body weight, it is commonly expressed in this unit.
For a more precise calculation: if your body fat is high, using lean body mass (LBM = body weight × (1 − body fat %)) instead of body weight helps avoid overestimating your needs.
Is it OK to eat a lot at once?+
Eating a large amount at once means the surplus is used as energy or excreted, so it is recommended to split your daily total across 3–5 servings.
Example: 20 g at breakfast + 30 g at lunch + 30 g post-workout + 30 g at dinner.
Do I need protein powder?+
However, for people who are busy and find it hard to get enough protein from meals, or who are heavier and need a larger amount, protein powder is a useful supplement.
Approximate protein content of common foods
・Chicken breast 100 g: about 23 g
・1 egg: about 6 g
・Firm tofu 100 g: about 7 g
・Salmon 100 g: about 20 g
・Greek yogurt 100 g: about 10 g
・Formula: recommended amount = body weight (kg) × goal-based coefficient (g/kg)
・Stokes T, et al. (2018). Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy. Nutrients, 10(2), 180.
・Morton RW, et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6), 376–384. (basis for the rough ceiling: gains plateau once total intake exceeds ~1.6 g/kg/day)
・Tagawa R, et al. (2021). Dose-response relationship between protein intake and muscle mass increase: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews, 79(1), 66–75. (lean mass rises with intake in a dose-dependent way, but the marginal gain shrinks at higher intakes)
・International Society of Sports Nutrition (ISSN) 2017 guidelines: 1.4–2.0 g/kg/day recommended for muscle growth
The results of this tool are a guideline based on international nutrition guidelines, and required amounts vary by individual constitution and health condition. People with kidney problems should be cautious with high-protein diets. For people with high body fat, calculating with lean body mass (LBM) is more accurate. If you have a pre-existing condition or are pregnant, please consult a doctor before use. For diet and nutrition management, please consult a doctor or registered dietitian. This service is intended to provide information only and is not a substitute for medical or nutritional guidance.
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