Lean mass based nutrition

Katch-McArdle Macro Calculator

Build your calorie target from lean body mass, not a generic height-age-sex estimate. Enter body weight, body fat, activity, and goal to get practical training-focused macros.

Calculate macros Why this formula?

✓ Katch-McArdle only ✓ Lean body mass driven ✓ Coaching-style adjustments

Nutrition tool

Lean mass calorie estimate
Practical macro targets
Simple coaching-style adjustments

Calculator

Your inputs

For best results, use a consistent body-fat estimate and update the calculator after two weeks of scale-weight and gym-performance trends.

Units

Body weight Pounds

Body fat % Required for Katch-McArdle because the formula uses lean body mass.

Activity level Multiplies Katch-McArdle BMR to estimate maintenance.

Goal Conservative defaults protect training quality and recovery.

Protein Grams per kg body weight. Use the higher end when dieting.

Fat Grams per kg body weight. Carbs fill the remaining calories.

Your targets

Daily plan

Calories —

BMR—

Maintenance—

Lean mass—

Goal adjustment—

Protein— g

Fat— g

Carbs— g

Protein target will appear after calculating.
Adjust only after 10–14 days of consistent tracking.

Get coaching help

The method

Only the Katch-McArdle formula

This page intentionally uses one lean-mass-based equation instead of switching between multiple calorie formulas. Katch-McArdle estimates resting needs from lean body mass, which makes it a better fit for lifters and body-composition coaching when body-fat data is available.

BMR = 370 + (21.6 × lean body mass in kg)

Find lean mass

Body weight is multiplied by the percentage of tissue that is not body fat.

Estimate maintenance

Katch-McArdle BMR is multiplied by your activity level to estimate TDEE.

Set macros

Protein and fat are anchored first, then carbs fill the calories left for training fuel.

FAQ

How to use these numbers

What if I do not know my exact body fat percentage?

Use your best consistent estimate from progress photos, calipers, a scan, or a trusted coach. The trend matters more than pretending the first estimate is perfect.

How should I adjust calories?

Track body weight averages, gym performance, hunger, and recovery for 10–14 days. If the trend does not match the goal, adjust by 100–200 calories and reassess.

Why are carbs the remaining calories?

Protein supports muscle retention and growth, fat protects baseline dietary needs, and carbs are adjusted to match your calorie target and training demands.