Find your body fat percentage with a tape measure: neck, waist and, for women, hip measurements. It also shows fat mass, lean mass and which category you fall into.
Double-check your measurements: your waist must be larger than your neck.
Estimate from a photo with AI → Save your progress in the app →The formula was developed by Hodgdon and Beckett (1984) for the U.S. Navy, which still uses it today to assess its service members. It estimates body fat from the relationship between body circumferences and height.
Body fat % = 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450, with measurements in cm.
Body fat % = 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450, with measurements in cm.
Stand relaxed, at the end of a normal exhale. Keep the tape snug without pressing into the skin. Measure twice and use the average.
Repeat every 2 to 4 weeks, at the same time of day and in the same way. The change between measurements tells you more than a single number.
American Council on Exercise classification, used as a reference by personal trainers.
| Range | Men | Women |
|---|---|---|
| Essential fat | 2 to 5% | 10 to 13% |
| Athletes | 6 to 13% | 14 to 20% |
| Fitness | 14 to 17% | 21 to 24% |
| Average | 18 to 24% | 25 to 31% |
| Above average | 25% or more | 32% or more |
In Trainer Connect, the physical assessment stores each student's measurements, calculates body composition, estimates it from a photo with AI and shows progress in a chart. Students see everything in their own app, in Portuguese, English, Spanish, French or German.
Start for freeStatistical estimate with a typical error of 3 to 4 percentage points. It does not replace an assessment by a health professional or tests like DEXA.