Protein Calculator
Calculate your ideal daily protein intake in grams based on body weight, activity level, and goal.
Quick summary: Daily protein needs range from about 0.8 g/kg body weight (sedentary, general health) up to 2.2 g/kg (fat loss while preserving muscle). This calculator applies research-backed ranges to your body weight and goal to give a concrete daily gram target.
Why protein needs vary so much
The commonly cited RDA of 0.8 g/kg body weight is the minimum to prevent deficiency in a sedentary adult — it is not an optimal target for anyone who exercises, is dieting, or is trying to build muscle. Resistance training and calorie deficits both increase the amount of protein the body needs to maintain and build muscle tissue, which is why sports nutrition research typically recommends roughly double the RDA for active individuals.
How this calculator works
Enter your body weight and select the profile that best matches your situation:
The gram-per-kilogram targets used
| Profile | Target | Rationale |
|---|---|---|
| Sedentary, general health | 0.8 g/kg | Standard RDA minimum to prevent deficiency |
| Regular exercise, maintenance | 1.4 g/kg | Supports recovery and muscle maintenance |
| Building muscle | 2.0 g/kg | Near the top of ranges shown to maximize muscle protein synthesis |
| Fat loss, preserving muscle | 2.2 g/kg | Higher protein helps offset muscle loss risk during a calorie deficit |
| Endurance athlete | 1.6 g/kg | Supports recovery from high training volume |
Worked example
A 70 kg person choosing "building muscle" (2.0 g/kg): daily target = 140 g protein = 560 kcal from protein, or roughly 35 g per meal across four meals.
Benefits and limitations
Benefits: translates general research ranges into a specific, actionable daily number based on your own body weight and situation.
Limitations: targets are based on total body weight, not lean body mass, so they may run slightly high for people with a higher body fat percentage — using body fat % (via a body fat calculator) to estimate lean mass can refine the target further.
Expert tips
- Spread protein across 3–4 meals rather than one large serving — this appears to support muscle protein synthesis better than front- or back-loading it.
- Include a mix of animal and plant protein sources for a complete amino acid profile.
- Protein needs rise, not fall, during a fat-loss phase — don't cut protein along with total calories.
- Recalculate after significant weight changes since the target scales with body weight.
Common mistakes
- Assuming more protein is always better beyond about 2.2 g/kg — extra intake beyond need is largely used for energy, not extra muscle.
- Using the sedentary RDA figure while training hard, which under-fuels recovery.
- Eating most protein in one meal instead of spreading it out.
Glossary
- RDA
- Recommended Dietary Allowance — the minimum intake to avoid deficiency in most healthy people.
- Muscle protein synthesis
- The biological process of building new muscle protein, stimulated by dietary protein and resistance training.
- Lean body mass
- Body weight minus fat mass — often a more precise basis for protein targets than total weight.
Frequently asked questions
It depends on activity and goals: roughly 0.8 g/kg for general sedentary health, up to 1.6–2.2 g/kg for people who train regularly or are dieting while trying to preserve muscle.
For most healthy people, higher protein intakes within these ranges are considered safe; people with pre-existing kidney disease should discuss protein intake with their doctor.
Lean mass is more precise, especially at higher body fat levels, but total body weight is a reasonable and simpler basis for most people.
Yes, when total intake and variety are adequate — combining different plant sources across the day covers the full range of essential amino acids.
Research generally favors spreading protein relatively evenly across 3–4 meals per day rather than concentrating it in one meal.
Sources & references
- International Society of Sports Nutrition Position Stand: protein — Journal of the International Society of Sports Nutrition
- Dietary Reference Intakes for protein — National Academies of Sciences
Author & reviewer
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