CalcPro

Protein Calculator

Recommended daily protein from body weight and goal.

Not medical advice. This tool is for general information and education only. It is not a diagnosis and cannot replace a doctor. Consult a qualified healthcare professional before acting on any result.

How it works

Your daily protein requirement depends on two factors: your body weight and how much physical stress you place on your muscles. The calculator multiplies your weight by a factor (called the protein multiplier) that corresponds to your lifestyle or goal. This multiplier ranges from 0.8 g/kg for sedentary individuals up to 2.0 g/kg for competitive athletes or those in a cutting phase.

The formula

Daily protein (grams) = Body weight (kg) × Protein multiplier (g/kg)

The multiplier is determined by your goal:

  • Sedentary (little or no exercise): 0.8 g/kg — the Recommended Dietary Allowance (RDA)
  • Active (exercise 3–5 days/week): 1.2 g/kg
  • Build muscle (strength training 4–6 days/week): 1.6 g/kg
  • Athlete/cutting (intense daily training or caloric deficit): 2.0 g/kg

Worked example

Let's calculate protein needs for a 75 kg person who strength trains 4 times per week.

  1. Identify inputs:

    • Body weight: 75 kg
    • Goal: Build muscle
    • Multiplier: 1.6 g/kg

  2. Apply the formula:

    • Daily protein = 75 kg × 1.6 g/kg
    • Daily protein = 120 grams

  3. Translate to food:

    • 3 oz (85 g) chicken breast ≈ 26 g protein
    • 1 cup Greek yogurt ≈ 20 g protein
    • 2 eggs ≈ 12 g protein
    • 1 cup cooked lentils ≈ 18 g protein
    • 1 oz almonds ≈ 6 g protein
    • Total: 82 g protein (additional 38 g from other meals or a protein shake)

Now consider a 65 kg sedentary adult:

  1. Identify inputs:

    • Body weight: 65 kg
    • Goal: Sedentary
    • Multiplier: 0.8 g/kg

  2. Apply the formula:

    • Daily protein = 65 kg × 0.8 g/kg
    • Daily protein = 52 grams

  3. Translate to food:

    • 3 oz salmon ≈ 25 g
    • 1 cup milk ≈ 8 g
    • 1 serving beans ≈ 15 g
    • Total: 48 g protein (easily met with a typical mixed diet)

Common mistakes

Confusing grams with ounces: Protein is measured in grams, not ounces. A 3 oz chicken breast contains roughly 26 g of protein, not 26 oz.

Using goal weight instead of current weight: The calculator works with your actual weight now. If you're overweight and want to use a lower figure, use your goal weight or lean body mass—but discuss this with a dietitian for accuracy.

Ignoring meal timing: Hitting your daily total matters more than perfect distribution, but spacing protein across meals (roughly 20–40 g per meal) maximizes muscle protein synthesis.

Forgetting hidden protein sources: Grains, vegetables, and dairy contribute protein. Track a few days with a nutrition app to see where your protein comes from before supplementing.

This calculator provides an estimate based on general nutrition science and is not a substitute for personalized medical or dietary advice. Individual needs vary by age, health status, metabolism, and training intensity. Consult a registered dietitian or doctor for guidance tailored to your circumstances.

Frequently asked questions

Why does protein need vary by activity level?

Your body uses protein to repair muscle tissue. Sedentary individuals need only enough to maintain basic body functions (0.8 g/kg, the RDA). Athletes and those building muscle create more micro-tears during exercise, requiring 1.6–2.0 g/kg to support recovery and growth.

Can I eat all my daily protein in one meal?

While possible, spreading protein across 3–4 meals (20–40 g per meal) optimizes muscle protein synthesis. Your body can only use about 20–40 g effectively per meal; excess is metabolized for energy rather than building muscle.

What if I'm overweight—do I use my actual weight?

For overweight individuals, using actual body weight can overestimate needs. Consider using lean body weight or goal weight instead, or consult a dietitian for personalized guidance.

Is this suitable for vegetarians or vegans?

Yes, the gram target applies to all diets. Plant-based proteins (legumes, tofu, nuts, seeds) often have lower amino acid density, so you may need slightly larger portions to hit the same gram target.

How does age affect protein requirements?

Adults aged 19–70 follow standard guidelines. Adults over 70 may benefit from 1.0–1.2 g/kg to prevent age-related muscle loss. Children and adolescents have higher per-kilogram needs; consult a pediatric dietitian.

Should I adjust protein intake on rest days?

Protein needs remain consistent whether you train or rest. Muscle repair happens during recovery, so adequate daily protein supports both active and inactive days.

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