Results update live as you type. Values convert automatically when you switch units.
Your Results
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Fill in your details and tap Calculate My Protein Needs to see your personalized daily protein target, grams per meal, and where you fall on the protein scale.
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grams / day
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RDA MinActiveStrengthAthlete Max
Per Meal
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grams per meal
From Protein
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calories/day
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Recommended Range For Your Goal
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Pregnancy / Lactation Addition
+25 g/day already included above
These figures are educational estimates, not medical advice. Consult a doctor or registered dietitian for guidance specific to your health situation.
Protein Needs by Activity Level
How your daily protein target changes across activity levels, at your current body weight.
How Much Protein Do You Really Need?
This free protein calculator gives you a personalized daily protein target based on your body weight, activity level, and goal — no guesswork required.
Whether you're using a protein calculator for weight loss to protect lean muscle during a diet, or trying to work out how much protein to build muscle effectively, the numbers below are grounded in the same ranges used by dietitians, strength coaches, and major health organizations.
What Does a Protein Calculator Actually Do?
A protein calculator converts your body weight, activity level, and goal into a practical daily gram target. Instead of guessing, you get a number you can track against nutrition labels or a food-tracking app. Most calculators, including this one, are built on the same core idea used by dietitians: protein needs scale with body weight, not a flat number that works for everyone.
The starting point is the RDA of 0.8 grams per kilogram of body weight (about 0.36 g per pound) — the minimum needed to prevent deficiency in a sedentary adult. Active people, dieters, and anyone trying to build muscle need meaningfully more than this baseline.
How the Calculation Works
Base Formula
Protein (g) = Body Weight (kg) × g/kg factor
Example: 77 kg × 1.6 g/kg = 123 g/day
US / Pounds Formula
Protein (g) = Body Weight (lbs) × g/lb factor
Example: 170 lbs × 0.73 g/lb = 124 g/day
The g/kg factor changes based on your selected activity level and goal — this calculator applies both automatically and shows you a healthy range, not just a single number.
Protein Intake Reference Table
Category
g per kg body weight
g per lb body weight
Sedentary (RDA minimum)
0.8 g/kg
0.36 g/lb
Light Exercise
1.0 g/kg
0.45 g/lb
Moderate Exercise
1.2 g/kg
0.54 g/lb
Heavy / Strength Training
1.6 g/kg
0.73 g/lb
Athlete / Intense Training
2.0 g/kg
0.91 g/lb
Weight Loss (fat-loss add-on)
+15–20%
+15–20%
Pregnancy / Lactation
+25 g/day (flat)
+25 g/day (flat)
These ranges reflect commonly cited guidance from dietetic and sports nutrition sources. Your exact needs can vary with muscle mass, health conditions, and training intensity.
Protein Calculator for Weight Loss
When you use a protein calculator for weight loss, expect a higher gram target than simple maintenance — usually 1.2 to 1.6 g/kg, and up to 2.0–2.4 g/kg for lean dieters. In a calorie deficit, your body is more prone to breaking down muscle for energy. Extra protein signals your body to preserve lean tissue instead, so the weight you lose comes mostly from fat.
Higher protein intake also increases satiety, meaning you feel fuller on fewer calories, and it has a higher thermic effect of food — your body burns slightly more calories digesting protein than it does digesting carbs or fat.
How Much Protein to Build Muscle?
Most research on resistance-trained individuals points to 1.6 to 2.2 g/kg of body weight (roughly 0.7–1.0 g/lb) as the sweet spot for muscle growth. Pushing meaningfully past this range doesn't appear to add extra muscle — the body can only use so much protein for repair and growth at a given training volume.
Spreading intake across 3 to 5 meals, each containing 20–40g of protein, supports muscle protein synthesis more consistently than getting most of your protein in one large meal. Pair your target with a structured resistance training program and a slight calorie surplus for the best results.
What Affects Your Protein Needs — and Where to Get It
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Training Volume
More frequent, higher-intensity resistance training increases muscle protein breakdown, which raises your daily protein requirement for recovery.
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Age
Older adults experience anabolic resistance, meaning muscles respond less efficiently to protein. Many experts suggest older adults aim for the higher end of the range.
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Diet Type
Vegetarians and vegans can hit their targets with legumes, tofu, tempeh, seitan, and grains — combining sources across the day covers all essential amino acids.
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Best Sources
Chicken breast, fish, eggs, Greek yogurt, cottage cheese, and lean beef are complete protein sources; lentils, chickpeas, and quinoa are strong plant-based options.
Frequently Asked Questions
How much protein do I need per day?
Most healthy adults need between 0.8 and 2.0 grams of protein per kilogram of body weight per day (about 0.36 to 0.9 grams per pound), depending on activity level and goal. Sedentary adults can use the RDA minimum of 0.8 g/kg, while people who strength train or want to build muscle typically need 1.6 to 2.2 g/kg. This protein calculator gives you a personalized target based on your own weight, activity level, and goal.
How much protein to build muscle?
To build muscle, most research points to a range of about 1.6 to 2.2 grams of protein per kilogram of body weight per day (roughly 0.7 to 1.0 grams per pound), spread across 3 to 5 meals. Eating more than this rarely produces extra muscle growth. Strength training combined with a slight calorie surplus and consistent protein intake is what drives muscle gain, not protein alone.
Does a protein calculator for weight loss give a different number?
Yes. A protein calculator for weight loss usually recommends more protein than maintenance, often 1.2 to 1.6 grams per kilogram of body weight (up to around 2.0 to 2.4 g/kg for very lean dieters). Higher protein intake during a calorie deficit helps preserve lean muscle mass, keeps you fuller for longer, and slightly increases the number of calories your body burns digesting food.
Can I get too much protein?
For most healthy adults, protein intake up to roughly 2.0 to 2.5 grams per kilogram of body weight per day is considered safe and is unlikely to cause harm. Very high, sustained intakes beyond that offer little additional benefit and may not suit people with pre-existing kidney conditions. If you have kidney disease or another medical condition, check with a doctor or registered dietitian before significantly increasing protein intake.
Is this protein calculator accurate for vegetarians and vegans?
The gram target from this calculator applies to anyone, including vegetarians and vegans. The main difference is food choice: since most plant proteins are incomplete on their own, aim to combine sources like legumes, grains, soy, and seitan throughout the day so you get all essential amino acids, and consider adding roughly 10 percent more total protein to account for slightly lower digestibility of some plant sources.
Should I eat more protein while pregnant or breastfeeding?
Yes. General guidance suggests adding about 25 extra grams of protein per day during pregnancy and while breastfeeding, on top of your normal target. This calculator includes an optional toggle that adds this amount automatically. Always confirm your specific needs with your OB-GYN or a registered dietitian.
Medical Disclaimer: The protein calculator results on this page are educational estimates, not medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider or registered dietitian regarding your individual nutrition needs, especially if you have a kidney condition, are pregnant, or are breastfeeding.
