The Protein Calculator estimates the daily amount of dietary protein adults require to stay healthy, based on your age, sex, height, weight, and activity level. It reports recommendations from several authoritative institutions so you can see the full healthy range.
The protein calculator estimates how much dietary protein you should eat each day to stay healthy, based on your age, sex, height, weight, and activity level. Protein is one of the three macronutrients (alongside carbohydrates and fat) and arguably the most important for building and repairing the body. Rather than giving a single number, this calculator reports the recommended protein range from several respected health authorities — the American Dietetic Association (ADA), the Centers for Disease Control and Prevention (CDC), and the World Health Organization (WHO) — so you can see both the minimum you need and a healthy upper target.
Getting enough protein matters for everyone, but the right amount varies widely from person to person. A sedentary office worker, a recreational gym-goer, and a competitive athlete all have different needs, and this tool adjusts its recommendations accordingly. Enter your details above to see your personalized protein targets in grams per day.
Protein is a macronutrient made up of smaller building blocks called amino acids. There are 20 amino acids, nine of which are "essential" — meaning your body cannot make them and must obtain them from food. Protein is found throughout the body: in muscle, bone, skin, hair, and virtually every cell and tissue. It is the main component of enzymes that power chemical reactions and of hemoglobin that carries oxygen in your blood. Unlike fat and carbohydrates, the body does not store protein in a dedicated reserve, so it must be supplied regularly through the diet.
Protein serves many critical functions: it builds and repairs tissue (especially muscle after exercise), makes enzymes and hormones, supports the immune system by forming antibodies, and provides a source of energy when needed. It also has the highest thermic effect of any macronutrient, meaning your body burns more calories digesting protein than it does digesting carbs or fat — one reason protein is emphasized in weight-management diets.
Choose US or Metric units, then enter your age, select your gender, and provide your height and weight. Pick the activity level that best matches your typical week — from sedentary through extra active. If you know your body-fat percentage and prefer the Katch-McArdle basis for the calorie-based range, open Settings to select it. Click Calculate to see your recommended protein intake from each institution, expressed in grams per day.
The calculator draws on three widely cited sources, each of which frames protein needs a little differently:
The ADA (now the Academy of Nutrition and Dietetics) bases its recommendation on body weight and activity. For sedentary adults it suggests roughly 0.8 to 1.0 grams of protein per kilogram of body weight, and for active individuals it recommends a higher range — about 1.0 to 1.8 grams per kilogram — to support muscle maintenance, repair, and growth. This is why the ADA figure on this calculator rises when you select a more active lifestyle.
The CDC expresses protein as a share of your total daily calories, following the Acceptable Macronutrient Distribution Range (AMDR) of 10% to 35% of calories from protein. Because it is tied to your calorie needs, this range grows as your activity level (and therefore your calorie expenditure) increases. The calculator first estimates your daily calorie needs from your body metrics and activity, then converts 10% and 35% of those calories into grams of protein.
The WHO publishes a safe lower limit for protein intake — the minimum considered adequate for a healthy adult — of about 0.83 grams per kilogram of body weight per day. This is a floor, not a target: it is the amount below which most people risk deficiency, so healthy intakes are generally at or above this level.
A closely related figure you may encounter is the Recommended Dietary Allowance (RDA) for protein, set at 0.8 grams per kilogram of body weight for the average sedentary adult. The RDA is defined as the minimum amount needed to meet the basic nutritional requirements of nearly all healthy people — in other words, enough to prevent deficiency, not necessarily enough to optimize muscle growth, athletic performance, or healthy aging. Many nutrition scientists argue that active people, older adults, and those trying to build or preserve muscle benefit from intakes well above the RDA, which is exactly why the ranges in this calculator extend higher for active individuals.
Protein comes from both animal and plant foods, and variety helps ensure you get all the essential amino acids.
Animal proteins are "complete," meaning they contain all nine essential amino acids in ample amounts. Excellent choices include chicken and turkey breast, lean beef, pork, fish and seafood, eggs, milk, Greek yogurt, and cheese. A typical chicken breast provides roughly 25-30 grams of protein, a large egg about 6 grams, and a cup of Greek yogurt around 20 grams.
Plant proteins such as lentils, beans, chickpeas, tofu, tempeh, edamame, quinoa, nuts, seeds, and whole grains are excellent too. Many are lower in one or more essential amino acids individually, but eating a variety of plant foods across the day easily provides a complete amino acid profile. Legumes and soy products are especially protein-dense, and quinoa and soy are among the few plant foods considered complete proteins on their own.
Research suggests that distributing protein fairly evenly across your meals — rather than eating most of it at dinner — may better support muscle protein synthesis. A practical approach is to include a solid protein source at each meal, aiming for roughly 20-40 grams per meal depending on your total target. For people who exercise, having protein within a few hours of a workout supports recovery, though total daily intake matters more than precise timing for most goals.
For healthy people, moderately high protein intakes are generally safe, and the upper end of the AMDR (35% of calories) is well tolerated. Very high intakes offer diminishing returns for muscle building and simply provide extra calories that can be stored as fat if they push you into a surplus. People with existing kidney disease should be more cautious and follow medical advice, since the kidneys process the byproducts of protein metabolism. Staying hydrated and choosing lean, varied protein sources helps keep high-protein eating healthy. As with any major dietary change, consult a healthcare professional if you have underlying health conditions.
Protein deficiency is uncommon in developed countries but can occur with very restrictive diets, in older adults with poor appetite, or during illness. Possible signs include loss of muscle mass and strength, slow wound healing, frequent infections, brittle hair and nails, swelling (edema), and persistent fatigue or hunger. If you suspect you are under-eating protein, increasing intake toward the ranges shown by this calculator — and consulting a dietitian if needed — is a sensible first step.
Behind the scenes, the calculator combines a few standard nutrition formulas. For the weight-based recommendations (ADA and WHO), it multiplies your body weight in kilograms by the appropriate grams-per-kilogram factor: about 0.83 g/kg for the WHO safe lower limit, and 0.8–1.0 g/kg (sedentary) or 1.0–1.8 g/kg (active) for the ADA range. For the calorie-based CDC range, it first estimates your Total Daily Energy Expenditure (TDEE) by calculating your Basal Metabolic Rate with the Mifflin-St Jeor equation (or Katch-McArdle if you supply body fat) and multiplying by your activity factor. It then takes 10% and 35% of those daily calories and converts them into grams of protein. Because these methods start from different assumptions, the three results rarely match exactly — and that is intentional. Seeing a minimum, a weight-based target, and a calorie-based range together gives you a well-rounded picture of a healthy protein intake rather than a single, potentially misleading number.
Protein plays a starring role in weight management for two reasons. First, it is the most satiating macronutrient, helping you feel full and reducing overall calorie intake — a meaningful advantage when you are eating in a deficit. Second, adequate protein helps preserve lean muscle during weight loss. When you lose weight, some of the loss can come from muscle unless protein intake and resistance training are sufficient; keeping protein high tilts that loss toward fat instead. For this reason, many dietitians recommend that people trying to lose weight eat toward the higher end of their protein range, often 1.2 to 2.0 grams per kilogram of body weight. The higher thermic effect of protein — the extra calories burned digesting it — is a small but welcome bonus. If you are cutting calories, treat protein as the macronutrient to protect first, trimming carbohydrates or fat before reducing protein.
While total daily protein is the most important factor, two finer points can help. Distribution — spreading protein across three or four meals rather than loading it all at dinner — keeps muscle-building signals elevated through the day. Quality matters too: complete proteins that contain all nine essential amino acids (and are rich in the amino acid leucine, a key trigger for muscle synthesis) are especially effective. Animal foods and soy are naturally complete; combining complementary plant foods, such as beans with grains, achieves the same result over the course of a day. For most people, hitting the daily target from a variety of quality sources is far more important than obsessing over precise timing.
It depends on your body weight and activity level. A common baseline is 0.8 grams per kilogram of body weight for sedentary adults, rising to roughly 1.0-1.8 g/kg for active people and those building muscle. Enter your details above to see personalized ranges from the ADA, CDC, and WHO.
Each frames protein needs differently. The WHO gives a safe minimum (about 0.83 g/kg), the ADA gives a weight- and activity-based range, and the CDC expresses protein as 10-35% of total daily calories. Together they show the full healthy span from minimum requirement to a generous upper target.
Yes. Athletes and people who train regularly generally benefit from more protein — often 1.2 to 2.0 g/kg — to support recovery, muscle repair, and growth. The calculator raises its recommendations automatically as you select a more active lifestyle.
It can be. Animal proteins are complete on their own, while most individual plant proteins are lower in one or more essential amino acids. Eating a variety of plant foods throughout the day easily provides all the essential amino acids, so well-planned vegetarian and vegan diets can meet protein needs fully.
No. Protein is necessary for muscle growth, but beyond roughly 1.6-2.2 g/kg there is little additional benefit for most people. Muscle growth also requires resistance training and adequate total calories; extra protein beyond your needs is simply used for energy or stored.
No. All calculations run entirely in your browser, and nothing you enter is uploaded or saved to any server, so your data stays private.
This Protein Calculator is provided for educational and general informational purposes and is not medical or nutritional advice. Recommended values are based on published guidelines and population averages and may not suit your individual needs. Consult a doctor or registered dietitian before making significant changes to your diet, especially if you have a medical condition such as kidney disease.