What this tool does
This is a measurement card. Ratios come from the tapes you enter. If neck and waist are filled, the Navy equation adds a body-fat estimate. Boer lean mass is context from scale weight and height.
How it works
Shoulder ÷ waist and waist ÷ chest are simple ratios. Navy math is the same as the body-fat calculator. None of it is a judging sheet.
Formula and methodology
Shoulder-to-waist = shoulders / waist. Navy %fat uses the published log10 circumference equations. Boer LBM is the usual height–weight estimate.
How to interpret the result
Track the same landmarks monthly. A 0.3 cm change is tape noise. A 4 cm waist drop over a cut is the story.
Example
Shoulders 122 cm, waist 82 cm → ratio 1.49. That is a shape number, not a moral score.
Common mistakes
- Flexing chest and sucking in waist on “progress” day only.
- Changing tape height every session.
- Chasing a ratio by shrinking calories into the floor.
When this estimate may be off
- Edema, a huge meal, or a pump you will not have tomorrow.
- You need DEXA or a coach’s callouts for a show.