Body & Metrics

FFMI (Fat-Free Mass Index) is a measurement of how much muscle mass you carry relative to your height, similar to BMI but based on lean mass instead of total weight.

Body fat percentage is the proportion of your total body weight that is fat, used to gauge body composition more accurately than weight alone.

Lean body mass is your total body weight minus fat mass — everything that isn't fat, including muscle, bone, organs, and water.

BMI (Body Mass Index) is a simple ratio of weight to height used to categorize people as underweight, normal, overweight, or obese.

Body recomposition is the process of losing fat and building muscle at the same time, changing your composition without necessarily changing your weight.

Bulking is a phase of eating in a caloric surplus combined with resistance training to maximize muscle growth, accepting some fat gain along the way.

Cutting is a phase of eating in a caloric deficit to lose body fat while preserving as much muscle as possible.

Waist-to-hip ratio is your waist circumference divided by your hip circumference, used as a simple indicator of fat distribution and health risk.

Bioelectrical impedance analysis (BIA) estimates body fat by sending a small electrical current through the body and measuring how it's resisted.

A DEXA scan is a body-composition scan using low-dose X-rays to measure fat, muscle, and bone with high accuracy.

Progress photos are consistent photographs taken over time to track visual changes in your physique that the scale doesn't capture.

Scale weight is your total body weight as measured by a scale — a useful but noisy data point that fluctuates day to day.

Water weight is short-term body weight from fluid retention, which can shift quickly and masks real fat changes on the scale.

Ideal body weight is an estimated healthy weight range for your height and build, used as a rough guideline rather than a precise target.