Protein Intake Calculator
Work out how much protein you need per day based on weight and activity level with this free protein intake calculator in your browser.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter your body weight.
- Optionally set grams per kg, then Calculate.
How it works
Multiplies body weight by a grams-per-kg target (default 1.6 g/kg). Active people often use 1.6–2.2 g/kg.
Worked example
80 kg at 1.6 g/kg. = 128 g a day.
Common mistakes
- Basing protein on total body weight when very overweight — lean or goal body weight gives a more realistic target.
- Chasing extreme amounts — beyond about 2.2 g/kg there is little added muscle benefit for most people.
Frequently asked questions
How much protein do I need to build muscle?
Roughly 1.6–2.2 g per kg of body weight per day, spread across meals, is the evidence-based range for muscle gain.
Can I get too much protein?
For healthy kidneys high protein is generally safe, but very high intakes displace other nutrients with no extra muscle benefit. Check with a doctor if you have kidney issues.
How much protein do I need?
Sedentary adults need roughly 0.8 g/kg; active people and those building muscle often aim for 1.6–2.2 g/kg. This is general guidance, not medical or dietary advice.
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Cite this tool
Zerdly. (2026). Protein Intake Calculator. Retrieved from https://www.zerdly.com/tools/protein-intake-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.