Protein Calculator
The Right Target Depends on Why You're Asking
Protein needs aren't one fixed number — the minimum to avoid deficiency is very different from the amount that supports muscle growth under heavy training. This calculator works from body weight and activity category, applying the gram-per-kilogram ranges cited by sports nutrition bodies like the ISSN, rather than a single flat recommendation that ignores what the protein is actually being used for.
The Formula
Protein (g/day) = Body Weight (kg) × Protein Factor (g/kg)
Protein Factor by Activity Category
| Category | g/kg range |
|---|---|
| Sedentary (RDA minimum) | 0.8 |
| Light activity / general health | 0.8 – 1.0 |
| Endurance athlete | 1.2 – 1.4 |
| Strength / resistance training | 1.6 – 2.2 |
| Active weight loss (preserve lean mass) | 1.6 – 2.4 |
A 70 kg strength-training individual, for example, lands in a range of 112 – 154 g/day using this table — noticeably above the 56 g/day sedentary RDA minimum for the same body weight.
Why the Range Widens at Higher Activity
- Preventing deficiency — the RDA figure of 0.8 g/kg is set to prevent nitrogen loss in a sedentary adult, not to optimize performance.
- Supporting muscle repair — resistance training creates more muscle protein breakdown that needs to be offset by higher intake to support net growth.
- Preserving lean mass in a deficit — protein needs actually rise, not fall, during active weight loss, since higher intake helps protect muscle while calories are restricted.
How to Use This Calculator
- Enter your body weight and choose kg or lb.
- Select your activity category.
- Select Calculate to see your recommended daily protein range in grams.
Related Calculations
Split your total calories across all three macros with the Macro Calculator, or check remaining calories for carbs and fat with the Carbs Calculator.