Body Fat Calculator - Free Estimate
Use the U.S. Navy method below for a quick body fat percentage estimate, or get instant AI-powered analysis from a photo—no tape measure needed.
The Problem with Manual Calculations
Research shows that manual body fat calculation methods have significant accuracy limitations. A study published in PMC comparing different methods found that the Navy formula has an accuracy of ±3-4% compared to DEXA scans—meaning if you calculate 20%, your actual body fat could be anywhere from 16-24%.
Navy Method
±3-4%- Free
- No equipment
- Quick
- Measurement error
- Doesn't account for muscle
- Formula limitations
Calipers
±3-5%- Inexpensive
- Portable
- Requires skill
- Only measures subcutaneous fat
- Inconsistent between testers
BIA Scales
±5-8%- Easy to use
- Track trends
- Hydration affects results
- Varies by time of day
- Often wildly inaccurate
DEXA Scan
±1-2%- Gold standard
- Full body analysis
- $75-150 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
Get body fat % in 10 seconds
PhysiqueAI uses AI trained on DEXA-validated data to estimate your body fat from a single photo. No measurements, no math, no margin for measurement error.
- No tape measure or calipers needed
- More consistent than manual measurements
- Track progress over time with photo history
- 15+ body composition metrics
- Works with mirror selfies
No credit card required
What the Research Says
Method Accuracy Comparison
A 2022 study in PMC comparing DEXA, BIA, and skinfold methods in athletes found significant differences between methods:
- BIA underestimated body fat by ~10% compared to DEXA in males
- Skinfold methods showed 6-7% lower readings than DEXA
- Results varied significantly between testers
Navy Method Limitations
Research from the U.S. Navy Body Composition Assessment study found that the tape method:
- Has ±3-4% accuracy when performed correctly
- Doesn't account for muscle mass differences
- Can misclassify muscular individuals as higher body fat
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
Get accurate results in 10 seconds
Skip the tape measure and guesswork. PhysiqueAI analyzes your photo with AI trained on DEXA-validated data. Just take a mirror selfie.
No credit card required • 1 free scan/month