Protein Calculator

Protein is the one macro that shouldn't be set as a fixed percentage of your total calories. Where carbs and fat are usually set relative to total calorie intake, protein needs are driven directly by your body weight, age, and training goal, which is why this calculator skips the calorie math entirely and works straight from those inputs.

What This Calculator Measures

This gives you a standalone gram target based on your weight, age, and training goal. It isolates your protein needs, without requiring you to map out a full daily calorie total and macro split.

The Formula

This calculator multiplies your weight in kilograms (or, for the Cutting / Fat Loss goal, your lean body mass) by a target amount of grams per kilogram, chosen based on your training goal and, for the Sedentary / General Health goal, your age.

Daily protein (g) = weight (kg) × target g/kg

Cutting / Fat Loss (with body fat % entered): Daily protein (g) = lean body mass (kg) × target g/kg

Lean body mass (kg) = weight (kg) × (1 − body fat % ÷ 100)

How This Calculator Computes Your Result

Enter your weight, age, and goal above. We convert your weight to kilograms if needed, apply the reference range for your selected goal, adjusted for age on the Sedentary / General Health goal, and based on lean body mass instead of total weight on the Cutting / Fat Loss goal if you provide your body fat percentage, and return a daily gram range. Expand the per-meal breakdown to see that range split across 3, 4, or 5 meals.

Reference Ranges

Reference ranges vary by training goal, and for one goal, by age as well.

Sedentary / General Health

The baseline recommended dietary allowance (RDA) is 0.8 g/kg of body weight for adults under 65¹. This is the minimum intake needed to avoid deficiency in most healthy adults, not necessarily an optimal target. For adults 65 and older, evidence supports a higher intake of 1.0 to 1.2 g/kg to help offset age-related muscle loss², since older muscle responds less efficiently to a given amount of protein.

Endurance Exercise

A joint position statement from the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine places general athlete protein needs at 1.2 to 2.0 g/kg, with endurance training toward the lower-middle part of that range³. Some newer research using more direct measurement methods suggests true endurance requirements may run higher than classical estimates, particularly during heavy or carbohydrate-restricted training⁴. This calculator uses a conservative 1.2 to 1.6 g/kg range rather than the higher end of that emerging evidence.

Strength / Resistance Training

A 2018 meta-analysis of 49 resistance-training studies found that gains in muscle mass plateau at approximately 1.6 g/kg of protein per day, with the surrounding confidence interval extending to 2.2 g/kg⁵. This calculator uses a 1.6 to 2.0 g/kg range built around that finding.

Muscle Building

For resistance training paired with a calorie surplus or maintenance intake, 1.6 to 2.2 g/kg is well supported by the same resistance-training evidence above, consistent with the International Society of Sports Nutrition’s general recommendation of 1.4 to 2.0 g/kg for exercising individuals⁶.

Cutting / Fat Loss

Protein needs to go up, not stay flat, during a calorie deficit, the goal is protecting muscle while losing fat. Research on resistance-trained, lean individuals during caloric restriction supports 2.3 to 3.1 g/kg of lean body mass, not total body weight⁷. If you enter your body fat %, this calculator uses that lean-body-mass-based range, without it, results fall back to the Muscle Building range as a bodyweight-based approximation.

Spread your protein across at least 3 to 4 meals throughout the day. Research suggests the anabolic benefit of a single meal’s protein plateaus around 0.4 to 0.55 g/kg per meal, so beyond that point, additional protein at one sitting adds little extra benefit⁸.