Daily Protein Calculator
Calculate your daily protein requirement in grams based on your body weight, activity level, and fitness goal. Use it when starting a diet, building muscle, or adjusting your nutrition plan.
About this calculator
Protein requirements vary significantly based on how active you are and what your body composition goals are. The foundational formula used here is: protein (g) = weight (kg) × activity_multiplier × goal_multiplier. Activity multipliers typically range from 0.8 g/kg for sedentary individuals up to 1.4 g/kg for moderately active people. Goal multipliers adjust further — muscle gain goals may apply a multiplier greater than 1, while weight loss goals prioritize protein to preserve lean mass. The baseline recommendation from the WHO is 0.8 g per kg of body weight for sedentary adults, while sports nutrition guidelines (ISSN, ACSM) recommend 1.6–2.2 g/kg for those engaging in resistance training. Protein supports muscle protein synthesis, enzyme production, immune function, and tissue repair. Spreading intake across 3–5 meals of 20–40 g optimizes muscle protein synthesis throughout the day.
How to use
Example: weight = 75 kg, activity level = moderately active (multiplier = 1.4), goal = muscle gain (multiplier = 1.2). Step 1: Enter weight = 75 kg. Step 2: Apply formula — protein = 75 × 1.4 × 1.2. Step 3: Calculate — 75 × 1.4 = 105, then 105 × 1.2 = 126 g. Result: this individual needs approximately 126 grams of protein per day. This could be met with sources like chicken breast (~31 g/100 g), Greek yogurt (~10 g/100 g), eggs (~6 g each), and legumes (~9 g/100 g cooked).
Frequently asked questions
How much protein do I need per day to build muscle?
For muscle hypertrophy, most sports nutrition research recommends consuming 1.6 to 2.2 grams of protein per kilogram of body weight per day. A 75 kg person training regularly should aim for 120–165 g of protein daily. Spreading this across 4–5 meals of 30–40 g each maximizes muscle protein synthesis, as the body can only efficiently utilize about 40 g per meal for this purpose. Consuming adequate calories alongside sufficient protein is equally important — protein cannot effectively build muscle in a significant calorie deficit.
What is the difference between protein needs for weight loss versus muscle gain?
During weight loss, protein requirements actually increase relative to maintenance because the body is at risk of breaking down muscle tissue for energy, especially in a calorie deficit. Research suggests 1.8–2.4 g/kg is optimal for preserving lean mass while losing fat. For muscle gain, 1.6–2.2 g/kg is the evidence-based range, with diminishing returns above 2.2 g/kg for most individuals. The key difference is that weight loss prioritizes protein as a muscle-sparing tool, while muscle gain uses it as a building block — but both require higher intake than the general sedentary recommendation of 0.8 g/kg.
Does activity level really change how much protein I need each day?
Yes, physical activity significantly increases daily protein requirements because exercise — particularly resistance and endurance training — causes micro-damage to muscle fibers that requires protein for repair and adaptation. A sedentary adult needs roughly 0.8 g/kg/day, while a recreational gym-goer needs around 1.2–1.6 g/kg, and competitive athletes may need up to 2.0–2.4 g/kg. The timing of protein intake around workouts also matters — consuming 20–40 g of protein within 1–2 hours post-exercise enhances muscle protein synthesis. Consistently under-eating protein relative to activity level leads to slower recovery, increased injury risk, and reduced performance gains.