Estimate body fat, BMI, waist-to-height ratio, waist-to-hip ratio, lean body mass, ideal weight, and FFMI.
Use tape measurements for a practical body-fat estimate.
Track waist-to-height and waist-to-hip trends.
Look beyond scale weight and estimate muscularity.
Scale weight alone does not tell you whether you are losing fat, losing muscle, or simply fluctuating with water and food volume. After 40, body composition matters because the goal is usually to lose fat while preserving or rebuilding lean tissue.
The BPF body composition calculators give users more context: waist trend, lean mass, FFMI, and body-fat estimate. Those numbers create a clearer picture than the scale by itself.
BMI can be a useful basic reference, but it does not account for muscle mass.
FFMI stands for Fat-Free Mass Index and estimates muscularity relative to height.
Use both when possible. Waist trend is simple and very practical.
Fitness calculators are educational estimates and coaching tools. They are not medical diagnosis or treatment. If you have pain, symptoms, medications, medical conditions, or injury concerns, consult a qualified professional.