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Protein Calculator

Free protein calculator: daily protein needs in grams from body weight and activity, from the 0.8 g/kg RDA to 2.0 g/kg for athletes and muscle gain.

Protein is the building block of muscle, enzymes, and hormones, and your daily requirement depends mainly on body weight and activity level. The Recommended Dietary Allowance is just 0.8 g per kg, but that only prevents deficiency — active people, older adults, and anyone trying to build muscle usually need more.

This calculator turns your body weight into a practical daily protein target in grams. Use the slider to set your protein target between 0.8 and 2.0 g/kg — the reference below maps each range to your training frequency. The result shows your daily grams, grams per kilogram, the calories protein contributes, and a per-meal target split over four meals.

Protein needs are not one-size-fits-all. A 70 kg active person needs around 112 g per day, while an athlete training for muscle gain may need up to 140 g. The calculator uses evidence-based ranges from the ISSN and PROT-AGE guidelines.

Enter your weight and slide to your protein level — the daily target updates instantly.

70 kg
30200
1.6 g/kg
0.82
0.8 prevents deficiency (RDA, sedentary); 1.0-1.2 for older adults; 1.2-1.6 for regular training (higher with more sessions); 1.6-2.0 for athletes building muscle.
Example
Example: 70 kg Active Adult

Set unit to Metric, weight to 70 kg, and protein to 1.6 g/kg:

Daily protein = 70 x 1.6 = 112 g
Calories from protein = 112 x 4 = 448 kcal
Share of 2,000 kcal = 448 / 2,000 = 22.4%
Per meal = 112 / 4 = 28 g

An athlete choosing 2.0 g/kg would target 140 g per day — 35 g per meal.

Key Insight: The protein factor changes your target by up to 150%: the same 70 kg person ranges from 56 g (0.8 g/kg) to 140 g (2.0 g/kg). Slide to the value that matches your real training, not your ambition.

Frequently Asked Questions

How much protein do I need per day?

It depends on body weight and activity. A sedentary adult needs about 0.8 g/kg, active people 1.2-1.6 g/kg, and athletes 1.6-2.0 g/kg. A 70 kg active person, for example, needs about 112 g per day.

Is 0.8 g/kg enough for me?

0.8 g/kg is the RDA that prevents deficiency in sedentary adults. Active people, older adults, and anyone training for muscle gain usually need 1.2-2.0 g/kg to support recovery and muscle maintenance.

Can I eat too much protein?

For healthy people, intakes up to about 2-2.5 g/kg are generally well tolerated. Extremely high intakes can add extra calories and strain kidneys in people with existing kidney disease, who should follow medical advice.

Should older adults eat more protein?

Yes. The PROT-AGE group recommends 1.0-1.2 g/kg for older adults to slow age-related muscle loss (sarcopenia) and support strength.

What foods are high in protein?

Lean meat, poultry, fish, eggs, dairy, soy, beans, lentils, nuts, and seeds. Spreading protein across 3-4 meals (about 25-40 g each) helps muscle building more than one large serving.

Do I need protein powder?

No. Whole foods can meet your needs; supplements are just a convenient way to hit a target, especially around training or when appetite is low.

This calculator provides estimates for educational purposes only and is not medical advice. Protein targets are general guidelines; individual needs vary with muscle mass, training volume, and health status. People with kidney disease should follow their doctor's protein limits. Consult a doctor or dietitian before making major dietary changes.

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