Strength & Upper Body Calculators
Five free calculators for muscle mass, grip strength, and relative-strength benchmarks. All based on NHANES data or peer-reviewed formulas.
What this category covers
Strength and muscle mass are among the strongest single predictors of long-term health, independent of BMI or body weight. This category groups five tools that measure different aspects of upper-body composition and strength:
- Grip strength — the most-cited single measurement in modern longevity research (Leong 2015, The Lancet).
- Lean body mass — total muscle mass estimate, useful for tracking sarcopenia and training progress.
- Arm circumference (MUAC) — a simple tape-measure proxy for upper-body muscle and nutritional status.
- Strength-to-weight ratio — relative strength benchmarks for the major lifts.
- Average grip strength — quick reference for grip strength norms by age and sex.
For beginner-to-elite standards on the major lifts (bench press, squat, deadlift, overhead press), see the Fitness Tests & Standards category.
All strength & upper body tools
How to use these together
Grip strength and arm circumference are both simple, tape- and dynamometer-based measurements you can take at home in under five minutes. Lean body mass and strength-to-weight ratio require a scale (and, for the second, a training log). All four return a percentile or relative-rank result so you can see where you stand compared to age-matched US adults.
For a deep read on the research, see our Upper Body Strength guide and Body Composition guide.