Body Fat Calculator - Free Estimate
Use the U.S. Navy method below for a quick body fat percentage estimate, or get an AI estimate from a photo—no tape measure needed.
The Problem with Manual Calculations
Research shows that manual body fat calculation methods have significant accuracy limitations. In a study of 1,904 active-duty soldiers, the US military's tape-measure equation (the Hodgdon equations in Army Regulation 600-9, the same family as the Navy method) differed from DEXA by about 4-6 percentage points (root-mean-square error). [source]
Navy Method
≈4-6 pts vs DEXA- Free
- No equipment
- Quick
- Measurement error
- Doesn't account for muscle
- Formula limitations
Calipers
≈3.5 pts SEE (trained tester)- Inexpensive
- Portable
- Requires skill
- Only measures subcutaneous fat
- Inconsistent between testers
BIA Scales
≈3-6 pts vs DEXA- Easy to use
- Track trends
- Hydration affects results
- Varies by device
DEXA Scan
Reference method (≈3 pts SEE vs lab model)- Common reference method
- Full body analysis
- About $75-$125 per scan
- Requires appointment
- Not practical for regular tracking
Navy Method Calculator
Your Measurements
Measure at navel level
Below Adam's apple
Skip the Tape Measure
Results in under a minute
PhysiqueAI estimates your body fat from a single photo with AI. No tape measure, no math. It's an estimate, best for tracking your trend with consistent photos.
- No tape measure or calipers needed
- Track progress over time with photo history
- Body fat, muscle, lean and fat mass estimates
- Works with mirror selfies
Free account • Full results with Premium
What the Research Says
Method Accuracy Comparison
A 2022 study in Children comparing DEXA, BIA, and skinfold methods in young football players found significant differences between methods:
- BIA read about 10 percentage points below DEXA in males
- Skinfolds read about 6 points lower than DEXA in men and about 11 in women
Navy Method Limitations
A 2019 study of U.S. Navy body composition assessment (Latour et al., International Journal of Kinesiology in Higher Education) found the tape method:
- Read lower than DEXA for men and higher for women
- Became more accurate with small changes to measurement sites and equations
Body Fat Percentage Ranges
Men
Competition bodybuilders, not sustainable
Visible abs, vascular
Lean, some ab definition
Healthy range for most men
Room for improvement
Women
Competition level, not sustainable
Very lean, athletic build
Fit appearance, toned
Healthy range for most women
Room for improvement
Track your trend from a photo
Skip the tape measure. PhysiqueAI estimates your body fat from a mirror photo with AI in under a minute.
Free account • Full results with Premium