Lean Mass Calculator

Lean mass guide

Lean Body Mass Protein Calculator

Calculate your daily protein target from lean body mass instead of total body weight for more accurate muscle-building and fat-loss nutrition.

Last updated: · Reviewed by the Lean Mass Calculator editorial team

Who this page is for

People who want to set daily protein intake based on lean body mass during bulking, cutting, or body recomposition.

Start with the main lean mass calculator, then use the related tools below when you need body fat, FFMI, protein, or calorie context.

Interactive Calculator

Use this calculator to find your specific numbers before continuing with the guide.

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Why protein targets should use lean mass, not total weight

Protein requirements are driven by lean tissue, not fat mass. Fat cells do not require dietary protein to maintain themselves. Setting protein targets from total body weight overshoots actual lean tissue needs, particularly at higher body fat percentages.

The gap is meaningful in practice. A 100 kg person at 35% body fat has 65 kg of lean mass. A protein target of 2.2 g/kg lean mass is 143 g per day. Based on total body weight, that same target becomes 220 g per day — 54 percent more than the lean tissue actually requires.

Using lean body mass as the protein reference produces targets that scale correctly with muscle mass regardless of how much fat a person carries.

Protein ranges by goal

For maintaining lean mass during a moderate calorie deficit, research supports roughly 1.8 to 2.7 g of protein per kilogram of lean body mass per day. The higher end of this range is appropriate for trained individuals or aggressive calorie cuts.

For muscle gain during a calorie surplus, 1.6 to 2.2 g/kg lean body mass is well-supported by the literature. Intakes above 2.2 g/kg are not harmful but show diminishing returns for most adults.

For general health and body composition maintenance without a strong training stimulus, 1.2 to 1.6 g/kg lean body mass is a practical starting point that keeps costs and meal planning reasonable.

How to calculate your protein target from lean mass

Use the lean mass calculator to get your lean body mass in kilograms. Then multiply that number by the low and high ends of your goal-specific protein range to find your daily target window.

The homepage lean mass calculator shows a single protein estimate using 2.2 g/kg lean body mass as a default active-person target. For a personalized range, calculate the lower and upper bounds manually using the values above.

Re-calculate your protein target whenever your lean body mass changes significantly — for example, after 8 to 12 weeks of consistent training and nutrition, or after a new DEXA scan.

Frequently asked questions

How much protein per kilogram of lean body mass?

For most active adults, 1.6 to 2.7 g of protein per kilogram of lean body mass covers the full range from general maintenance to aggressive muscle preservation during a cut. A common default target for people actively training is 2.2 g/kg lean body mass.

How much protein per pound of lean body mass?

To convert: divide the kg-based target by 2.205. A target of 2.2 g/kg lean mass is roughly 1.0 g per pound of lean mass. The full active range of 1.6 to 2.7 g/kg converts to approximately 0.73 to 1.22 g per pound of lean mass.

Should I use lean body mass or total body weight for protein targets?

Lean body mass is more accurate because protein requirements are driven by lean tissue, not fat. For lean individuals under 20% body fat, the difference is small and either approach works. For people at higher body fat percentages, using lean mass gives a more appropriate and lower protein target.

Does protein need change during a cut versus a bulk?

Yes. Protein needs are generally higher during a calorie deficit because the body faces more pressure to catabolize lean tissue for energy. Most research on muscle preservation during dieting supports 2.0 to 3.1 g/kg lean mass. During a calorie surplus, 1.6 to 2.2 g/kg is typically sufficient for muscle protein synthesis.

What happens if I exceed my lean mass protein target?

Protein consumed beyond the body's synthetic capacity is oxidized for energy. It is not harmful for healthy adults in realistic food quantities, but it displaces carbohydrates and fats, adds calories, and provides no additional muscle-building benefit above about 2.5 to 3 g/kg lean mass.

How often should I recalculate my protein target from lean mass?

Recalculate whenever your lean body mass changes meaningfully — typically after 8 to 12 weeks of consistent training and nutrition, or immediately after a new DEXA scan. If you are actively gaining or losing lean mass, quarterly recalculation keeps your protein targets calibrated to your current body composition.

Sources & references

The estimates on this page use published lean body mass equations and clinical reference ranges. See the full reference charts on the lean body mass chart hub.