About
A no-nonsense protein tool
Protein Calculator exists for one reason: to give people a fast, trustworthy estimate of how much protein they should eat each day, without sign-ups, paywalls, or overcomplicated spreadsheets.
Evidence first
Every multiplier and adjustment traces back to published sports-nutrition research or official dietary reference intakes — not a hunch or a trend.
Private by default
Your numbers are calculated in your browser and never stored or sent anywhere. There is no account and no tracking of your inputs.
Built for real goals
Whether you are losing fat, building muscle, or just staying healthy, the tool adapts to your activity level, age, and dietary preference.
Our methodology
The calculator estimates daily protein using grams of protein per kilogram of body weight, with multipliers drawn from the International Society of Sports Nutrition position stand on protein and exercise and the USDA Dietary Reference Intakes. The 0.8 g/kg RDA covers the minimum for sedentary healthy adults; higher ranges (1.6–2.4 g/kg) apply to fat loss, muscle gain, and athletic performance. Adults over 60 receive an automatic +0.2 g/kg adjustment to counter age-related muscle loss, and vegetarian and vegan diets receive +5% and +10% respectively for the lower digestibility of some plant proteins. You can read the full breakdown in our protein guide.
Who this is for
The tool is designed for healthy adults aged 18 and over who want a practical daily protein target. It is not intended for children, pregnant or nursing individuals, or people managing kidney disease, liver disease, diabetes, or other medical conditions — those groups should work with a physician or registered dietitian for personalized guidance.
How we keep it free
The site is supported by advertising. To respect both readers and Google’s policies, ads appear only alongside substantial original content — such as the calculator and our guide — and never on thin pages like this one. We do not sell your data, because we never collect it; see our privacy policy for the details.
Disclaimer
Protein Calculator provides general information for educational purposes only. It is not medical advice and is not a substitute for consultation with a qualified healthcare professional. Always consult a physician or registered dietitian before making significant changes to your diet.