Protein Calculator
Find out how many grams of protein you need per day based on your weight, activity level, and goal.
Why protein needs vary so much by activity level
Protein is the building block your body uses to repair and grow muscle tissue, produce enzymes and hormones, and support your immune system. Someone who's sedentary needs meaningfully less protein than someone training regularly, because exercise — particularly resistance training — creates micro-damage in muscle fibers that protein is needed to repair. Without enough protein, that repair process is incomplete, which can blunt strength and muscle gains even if every other part of a training program is done correctly.
Sports nutrition research generally recommends a range rather than a single number, because individual protein needs are influenced by training intensity, age, and overall calorie intake. This calculator uses activity-adjusted ranges commonly cited in sports nutrition literature: lower amounts for sedentary adults focused on general health, and higher amounts for people actively training or trying to build muscle.
Why protein needs increase during weight loss
It might seem counterintuitive, but protein needs often go up, not down, when you're trying to lose weight. When you eat in a calorie deficit, your body is more likely to break down muscle tissue for energy alongside fat, unless you give it enough protein to signal that muscle should be preserved. This is why the calculator recommends a higher protein target specifically for the weight-loss goal — it's a defense mechanism against losing lean muscle mass along with body fat.
Spreading protein across meals
Your body can only use a limited amount of protein for muscle repair in a single sitting — research suggests diminishing returns somewhere in the 30-40g range per meal for most people. That's why this calculator also shows a per-meal breakdown assuming three meals a day: it's generally more effective to spread your total protein intake across multiple meals than to consume most of it in one sitting.
Is more protein always better?
Not necessarily. These figures reflect ranges commonly recommended in sports nutrition research; consistently exceeding them provides diminishing returns for most people and simply displaces calories that could otherwise come from carbohydrates or fats needed for training energy and hormone health.
Should I split protein evenly across meals?
Spreading protein across 3-4 meals is generally considered more effective for muscle maintenance and growth than eating it all in one meal, since your body can only make efficient use of a certain amount at a time.
Does protein source matter?
Complete protein sources (meat, fish, eggs, dairy, soy) contain all essential amino acids your body needs but can't produce on its own. If you rely heavily on incomplete plant proteins, combining different sources across the day (like rice and beans) can help you get a complete amino acid profile.
How does this relate to the calorie calculator?
Your total daily calories and protein target work together — this calculator gives you a protein gram target, while the calorie calculator on this site shows how that protein fits into your overall calorie and macro plan for your specific goal.
This calculator provides general estimates for informational purposes only and is not a substitute for personalized advice from a doctor or registered dietitian.