Your Body Composition Toolkit
Six free calculators designed by an exercise physiologist. Every calculation runs in your browser — your data never leaves your device.
Browse All Tools
Six free calculators designed by an exercise physiologist. Every calculation runs in your browser — your data never leaves your device.
Browse All Tools
Navy method, YMCA method, 3-site/7-site skinfold with Jackson-Pollock equations. Age/sex/ethnicity adjustments.
Side-by-side health risk interpretation. Detects BMI false positives for athletes and "normal weight obesity" flags.
Calculate lean mass from weight and BF%. Bone mass estimate, organ mass reference ranges, residual mass breakdown.
Site selection guide, measurement log with mm trend chart, technician error warnings. LocalStorage saves your history.
Hydration status impact, electrode placement, consumer scale vs professional device accuracy, morning vs evening variance.
Bulk rate (+0.25-0.5% body weight/week), cut rate (-0.5-1.0%), maintenance calories, protein target, timeline to goal BF%.
How to Track Lean Body Mass Progress Without Obsessing Over the Scale — BodyCompCheck
The Perfect Morning Routine for Consistent BIA Readings — BodyCompCheck
How a Home BIA Scale Nearly Cost David His Competition Prep — BodyCompCheck
The 7-Site Skinfold Protocol: Step-by-Step for Self-Measurement — BodyCompCheck
Navy Method vs. 3-Site Skinfold: Battle of the Estimators — BodyCompCheck
Consumer BIA Scales vs. Professional Devices: The Real Accuracy Gap — BodyCompCheck