Protein Need Calculator

Protein is the most important macronutrient for muscle maintenance, recovery, satiety, and metabolic function. Your daily requirement depends on body weight, activity level, age, and goals. The standard RDA is actually the minimum to prevent deficiency, and most active people need considerably more.

Formula: Daily Protein (grams) = Body Weight (kg) × Protein Factor

Or in pounds: Daily Protein (grams) = Body Weight (lbs) × Protein Factor

Protein targets in g/kg, by activity level and goal

Every cell here is what the calculator uses, so the two cannot drift apart.

The 0.8 g/kg figure in the top-left is the RDA, and it is worth knowing what that number actually is. It is the amount that prevents deficiency in most healthy adults, not the amount that is optimal for anything. Nearly every other row is higher for a reason.

Losing fat needs more protein than building muscle

This surprises people, and it is the row most often got wrong. In a calorie deficit the body is more willing to break down muscle for fuel, so protein requirements go up during a diet, not down. Cutting calories and cutting protein at the same time is how people lose weight and end up softer at a lower body weight.

Age changes the answer

Muscle in older adults responds less to the same amount of protein, which is called anabolic resistance. The practical consequence is that the guideline floor for adults over 65 is around 1.2 g/kg even for someone entirely sedentary, well above the 0.8 RDA. This calculator flags it when you enter an age of 65 or over.

Worked example

A 78 kg person training 3 to 5 days a week and building muscle:

Target = 78 × 1.6 to 2.0 = 125 to 156 grams a day, so aim for about 140.

Split across 4 meals that is 35 g each, which comfortably clears the 0.4 g/kg (31 g) per-meal dose needed to switch on muscle protein synthesis.

Protein content of common foods:

• Chicken breast (100g): 31g protein
• Eggs (1 large): 6g protein
• Greek yogurt (170g): 17g protein
• Tuna (100g): 29g protein
• Cottage cheese (100g): 12g protein
• Lentils (cooked, 100g): 9g protein
• Whey protein powder (1 scoop): 20–25g protein
• Tofu (100g): 8g protein
• Black beans (100g): 8.9g protein

Timing: Research shows distributing protein evenly across 3–5 meals optimizes muscle protein synthesis better than consuming it all in one or two meals.