Protein Calculator

"Eat more protein" is easy advice to give and hard advice to follow, because nobody eats percentages. This calculator turns your body weight and activity level into a concrete daily protein target in grams — the number you can actually compare against food labels, meal plans and protein shakes.

Quick Answer

Daily protein (g) = body weight (kg) × an activity factor. The baseline factor is 0.8 for a sedentary adult (the official recommended dietary allowance), rising through about 1.2–1.4 for regularly active people and up to 1.6–2.2 for building muscle or training intensely.

Why Protein Needs Are Quoted Per Kilogram

Protein is not stored the way fat and carbohydrate energy are; the body maintains a pool of amino acids that it draws on to repair muscle, make enzymes and hormones, and support the immune system. The amount you need scales mainly with how much lean tissue you maintain and how hard you train it, which is why guidelines express intake relative to body weight rather than as one fixed number for everyone.

The floor of the range, 0.8 grams per kilogram, is the RDA: the intake that covers the needs of nearly all healthy sedentary adults. It is a minimum to avoid deficiency, not an optimum for sport. Research on athletes and people in structured training consistently supports higher intakes — roughly 1.2 to 1.6 g/kg for endurance and mixed training, and 1.6 to 2.2 g/kg during dedicated muscle-building phases or when dieting to lose fat while protecting muscle. Older adults also tend to benefit from the middle of the range, because ageing muscle responds less sensitively to protein.

What a Day at 120 Grams Actually Looks Like

Gram targets stay abstract until they are translated into food. Using typical values — a large egg at about 6 g of protein, 100 g of cooked chicken breast at about 31 g, a 170 g pot of Greek yogurt at about 17 g, and a glass of milk at about 8 g — the example target of 120 g builds up unremarkably: two eggs and yogurt at breakfast (about 29 g), a chicken-breast lunch with grains and vegetables (about 40 g), a glass of milk or a protein-rich snack in the afternoon (about 10–15 g), and a dinner built around fish, meat, tofu or legumes (about 40 g). No shakes or supplements are required to reach it, though they can be convenient.

Vegetarian and vegan eaters follow the same arithmetic with different building blocks: tofu, tempeh, lentils, beans, edamame and Greek-style plant yogurts carry the load, and because individual plant proteins are each lower in some essential amino acid, variety across the day does the work that a single source does in an omnivore diet. The total matters more than the source for most healthy people.

How to Use This Protein Calculator

1. Weigh yourself and note your weight in kilograms (or convert from pounds first — divide by 2.205).
2. Choose the activity or goal level that honestly matches your routine.
3. Enter your weight and selection into the calculator.
4. Read your recommended daily protein intake in grams.
5. Spread the target across the day's meals — roughly even portions at each meal suit most people.
6. Revisit the number when your weight or training changes materially.

Worked Example: A 75 kg Person

Consider someone weighing 75 kg who lifts weights several times a week with the goal of building muscle. At a factor of 1.6 g/kg, the target is 75 × 1.6 = 120 grams of protein per day, which supplies 120 × 4 = 480 kcal of the day's energy. The same person living sedentarily would need only 75 × 0.8 = 60 grams — the goal and activity level double the target, which is exactly why a single universal figure makes little sense.

The same 75 kg body weight at each common level:

• Sedentary (0.8 g/kg) → 60 g per day
• Recreationally active (1.2 g/kg) → 90 g per day
• Endurance training (1.4 g/kg) → 105 g per day
• Building muscle (1.6–2.2 g/kg) → 120–165 g per day

Does Timing Matter? Spreading Protein Across the Day

Once the daily total is set, distribution is the second-order question. Muscle protein synthesis responds to each protein-containing meal and then becomes refractory for a few hours, which is why researchers often suggest spreading intake across three or four meals rather than eating most of it at dinner — the pattern a typical day naturally produces, with a light breakfast and a heavy evening meal, is close to the worst arrangement. One widely cited review proposed roughly 0.4 g per kilogram per meal across four meals as a practical way to reach a 1.6 g/kg daily target. Each of those meals ideally contains a leucine-rich protein source — dairy, eggs, meat, fish or soy — because leucine is the amino acid that most strongly triggers the muscle-building signal. None of this outweighs the daily total, which remains the first thing to get right.

Where People Commonly Go Wrong

The most expensive mistake is confusing the units of the factor. A figure like "one gram per pound" circulates in gym culture; applied carelessly as one gram per kilogram it underfeeds, and the reverse error — using a per-kilogram factor against a weight in pounds — inflates the target by a factor of 2.2. Always check which unit a recommendation uses.

Second, more is not endlessly better. Above roughly 2.2 g/kg, studies find little additional muscle benefit for most people; the extra protein is simply burned as (costly) energy. Third, protein targets assume your total calories are adequate. In a steep calorie deficit the body uses more protein for fuel, so dieters are usually advised toward the upper end of their range. Finally, protein quality matters alongside quantity: animal foods and soy provide all essential amino acids in one package, while plant-based eaters reach the same coverage by mixing sources such as grains and legumes across the day.

These figures are general-information estimates for healthy adults. Anyone with kidney disease or another condition affecting protein metabolism should follow the intake set by their doctor or dietitian instead.

Planning the Rest of the Plate

Protein is one of three macronutrients, and a target for it sits inside a total calorie budget. The calorie calculator establishes that budget, and the companion carbohydrate calculator and fat intake calculator divide what remains into the other two macros, so the three numbers add up to a coherent day of eating.