Protein Requirement Calculator
Estimates how many grams of protein you need daily based on your body weight and activity level. Use it to optimise muscle repair, recovery, and satiety on any diet.
About this calculator
Daily protein requirements scale with body weight and how hard you train. This calculator uses the formula: Protein (g/day) = weight_kg × (1 + activityLevel × 0.1). The base multiplier of 1 g per kg represents the minimum needed for a sedentary individual to prevent muscle breakdown. Each increment of activity level adds 10% more protein per kg, reflecting increased muscle protein synthesis demands from exercise. For context, general health guidelines suggest 0.8 g/kg for sedentary adults, while sports nutrition research recommends 1.6–2.2 g/kg for those doing resistance training. Adequate protein supports muscle repair after exercise, promotes satiety to aid fat loss, and helps preserve lean mass during a calorie deficit. Spreading intake across 3–5 meals maximises muscle protein synthesis throughout the day.
How to use
Suppose you weigh 75 kg and have a moderate activity level of 3 (e.g. training 3–4 days per week). Apply the formula: Protein = 75 × (1 + 3 × 0.1) = 75 × (1 + 0.3) = 75 × 1.3 = 97.5 g/day. So you should aim for approximately 98 g of protein per day. That could be spread across meals — for example, 30 g at breakfast, 35 g at lunch, and 33 g at dinner — to maximise muscle protein synthesis throughout the day.
Frequently asked questions
How much protein do I need per day to build muscle?
For muscle hypertrophy, the current sports nutrition consensus recommends 1.6–2.2 g of protein per kg of bodyweight per day, with 2.2 g/kg being the upper range for serious strength athletes. Below 1.6 g/kg, muscle protein synthesis may not be fully maximised even with resistance training. Total daily protein matters more than the exact timing, but spreading it evenly across 4–5 meals of 25–40 g each has been shown to optimise anabolic response throughout the day.
Does protein requirement change when you are trying to lose weight?
Yes — during a calorie deficit, protein requirements actually increase compared to maintenance. When calories are restricted, the body is more likely to break down muscle for energy, so higher protein intake (up to 2.2–2.4 g/kg) helps preserve lean mass. High protein intake also increases satiety, reducing hunger on a calorie-restricted diet. Studies consistently show that higher-protein diets during weight loss result in better body composition outcomes — more fat lost and less muscle lost — compared to lower-protein approaches.
What happens if you eat too much protein?
For healthy individuals with normal kidney function, consuming moderately high protein (up to 2.5 g/kg/day) is considered safe by current research. Excess protein that cannot be used for muscle repair or metabolic functions is converted to glucose or fat and stored as energy — it does not directly cause kidney damage in healthy people, though those with pre-existing kidney disease should consult a doctor. The main practical downside is that very high protein intake crowds out other macronutrients, potentially reducing carbohydrate availability needed for high-intensity training performance.