Protein Calculator
Estimate your daily protein needs based on your body weight and activity, in grams per day.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general educational estimates only and is not medical advice. It does not diagnose, treat, or replace guidance from a qualified healthcare provider. Consult a doctor for decisions about your health.
About the Protein Calculator
The protein calculator estimates how many grams of protein you need each day based on your body weight, activity level and goal. It starts from the recommended dietary allowance of 0.8 g per kilogram for sedentary adults and increases the target as activity rises, in line with sports-nutrition guidance of roughly 1.4–2.0 g/kg for people who exercise. If you are losing weight or trying to build muscle, the target rises to at least 1.6 g/kg (up to 2.2 g/kg), because higher protein helps preserve and build lean mass. The result shows the grams per day and the per-kilogram rate used.
How to use it
- 1Select your sex and enter your age, weight and height.
- 2Choose your activity level.
- 3Choose your goal: lose weight, maintain or gain muscle.
- 4Press Calculate to see your daily protein target in grams.
Worked example
a 75 kg adult who exercises 3–5 days a week and wants to maintain weight gets 1.3 g/kg, or about 98 g of protein a day. Switching the goal to “Lose weight” raises the rate to 1.7 g/kg, or about 128 g a day.
How it works
How it works
The target starts at the 0.8 g/kg recommended dietary allowance for sedentary adults and rises with activity: 1.0 g/kg (light), 1.3 g/kg (moderate), 1.6 g/kg (active) and 1.8 g/kg (very active). If your goal is to lose weight or gain muscle, the target rises to at least 1.6 g/kg (maximum 2.2 g/kg) to help preserve or build lean mass.
Who it is for
Active adults, people in a calorie deficit, strength athletes and anyone checking whether their diet contains enough protein.
Why it helps
Protein needs scale with body weight and training, so a personal target is more useful than a generic daily value.
Common use cases
- Setting a protein target while dieting
- Planning protein intake for a strength-training programme
- Spreading protein across meals (roughly 20–40 g per meal)
Common mistakes to avoid
- Counting the weight of a food as its protein content — 100 g of chicken breast contains about 31 g of protein.
- Using goal weight instead of current weight when you are far from your goal.
Frequently asked questions
A:Sedentary adults ~0.8 g/kg; active and strength athletes 1.6–2.2 g/kg.
A:Very high intakes offer little extra benefit for most people.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow recognised clinical references — including WHO BMI classifications, the Mifflin-St Jeor equation, and Naegele’s rule — and are periodically checked against published reference values.
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources
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