Protein Calculator
Enter your weight and activity level to estimate your daily protein needs in grams. Adjust the goal for maintenance, muscle gain or fat loss.
Reviewed by the ToolNestr Editorial Team — July 2026
Enter your weight and goal to see your protein target.
About protein needs
Protein is the building block of every cell in your body. It is essential for muscle repair, enzyme production, immune function and hormone synthesis. Your daily protein requirement depends primarily on your body weight and how active you are. The American College of Sports Medicine recommends 1.2–1.7 g per kg of body weight for athletes, while the RDA for sedentary adults is just 0.8 g per kg. This calculator helps you find the right target based on your lifestyle. For a broader view of your nutrition, see the Macro Calculator and Lean Body Mass Calculator.
⚕️ For general information only. Consult a professional before making major dietary changes.
How it works
Your daily protein target is calculated by multiplying your body weight (in kilograms) by a factor that corresponds to your activity level and goal. The factor ranges from 0.8 g/kg for sedentary individuals up to 2.2 g/kg for bodybuilders and those in a calorie deficit trying to preserve muscle. The calculator shows the result in grams, along with the per-meal breakdown for three meals and the total calories protein contributes (protein has 4 calories per gram).
The formula explained
Protein (g) = weight (kg) × protein factor
For example, a 75 kg person with a moderate activity goal (1.6 g/kg):
75 × 1.6 = 120 g of protein per day = 480 calories
Worked example
A 68 kg woman who exercises 4 days per week (moderate activity, 1.6 g/kg) wants to know her protein target.
Bodybuilder on a cut
High protein (2.0–2.2 g/kg) during a calorie deficit helps preserve muscle mass while losing fat. This is critical for body composition.
Vegan athlete
Plant-based eaters may benefit from slightly higher protein targets (2.0 g/kg) because plant proteins have lower digestibility and amino acid profiles.
Older adult
Higher protein intake (1.2–1.6 g/kg) helps counteract sarcopenia and maintain bone density, strength and independence as you age.
Meal prepper
Know the exact grams of protein needed per meal to plan your weekly grocery shop and batch-cook with confidence.
How to use this calculator
Enter your weight
Use your current body weight in either metric or imperial units. For best results, use your morning weight after the bathroom.
Select your goal
Choose from maintenance, light activity, moderate activity, very active or bodybuilding. Each corresponds to a g/kg factor.
Read your target
See your daily protein target in grams, the per-meal amount and the calorie contribution. Use a tracking app to stay on target.
Tips for hitting your protein target
Spread it across meals
Muscle protein synthesis responds best to 20–40 g of protein per meal, spread across 3–4 meals. A single huge dinner is less effective than balanced distribution.
Include protein at breakfast
Many people eat very little protein at breakfast. Adding eggs, Greek yoghurt or a protein shake at breakfast helps spread your intake evenly across the day.
Use protein supplements wisely
Whole foods should be the foundation, but a whey or plant protein shake can help bridge the gap when you are short on time or appetite.
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Frequently asked questions
How much protein do I need per day?
For sedentary adults, the RDA is 0.8 g per kg of body weight. For active individuals, 1.2–1.6 g per kg is recommended. For muscle building and fat loss, 1.6–2.2 g per kg is optimal.
Can I eat too much protein?
For healthy individuals, protein intakes up to 2.5 g per kg are safe. Very high intakes (above 3 g/kg) are unnecessary and may cause digestive discomfort. People with kidney disease should consult a doctor before increasing protein.
Do I need more protein as I age?
Yes — older adults (65+) benefit from higher protein intake (1.2–1.6 g/kg) to counteract sarcopenia (age-related muscle loss) and maintain strength and mobility.
What are the best sources of protein?
Complete proteins (all essential amino acids) include meat, fish, eggs, dairy, soy and quinoa. Plant-based eaters should combine different sources throughout the day to ensure a full amino acid profile.
Should I eat protein before or after exercise?
Total daily protein intake matters more than timing. Spreading protein evenly across meals (3–4 servings of 20–40 g each) is more effective than loading up post-workout alone.