How to Measure Body Fat at Home
Updated May 2026 · Last reviewed: May 2026
Body fat percentage is a better metric than body weight for tracking body composition changes. But measuring it accurately at home is challenging. Here's a comparison of the most common methods.
The Navy Circumference Method
The U.S. Navy developed a body fat estimation method using just a tape measure. It's free, requires no special equipment, and is reasonably accurate for most people. Use our Body Fat Calculator to compute your percentage.
Male formula: Body fat % = 86.010 × log10(waist - neck) - 70.041 × log10(height) + 36.76
Female formula: Body fat % = 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387
Accuracy: ±3-4%. Good for tracking trends over time. Consistent measurement technique is critical.
Skinfold Calipers
Calipers measure subcutaneous fat at specific body sites (typically 3 or 7 sites). They're inexpensive ($10-50) and more accurate than circumference methods when done correctly.
Accuracy: ±3-5% with practice. The learning curve is real — have someone experienced measure you, or practice on yourself until you get consistent readings.
Pros: Cheap, portable, directly measures body fat. Cons: Requires practice, can't measure visceral fat, uncomfortable for some users.
Smart Scales (BIA)
Bioelectrical Impedance Analysis (BIA) sends a tiny electrical current through your body and estimates body fat based on resistance. Most smart scales use this technology.
Accuracy: ±5-8%. Highly affected by hydration status, time of day, and recent meals. Good for tracking trends if measured under consistent conditions (same time, same hydration state).
Pros: Effortless, gives other metrics (muscle mass, bone density estimates). Cons: Inaccurate absolute readings, easily manipulated by hydration.
DEXA Scans (Gold Standard)
Dual-Energy X-Ray Absorptiometry is the most accurate widely available method. It uses low-dose X-rays to measure bone density, fat mass, and lean mass by body region.
Accuracy: ±1-2%. This is the benchmark against which all other methods are compared.
Pros: Most accurate, regional breakdown (arms vs legs vs trunk). Cons: Expensive ($50-150 per scan), requires a facility visit, very low radiation exposure.
Which Method Should You Use?
- Best free method: Navy circumference (use our calculator!)
- Best home method: Skinfold calipers with 7-site measurement
- Best low-effort method: Smart scale (morning, fasted, after bathroom)
- Most accurate: DEXA scan (every 3-6 months to calibrate your home methods)
Tips for Consistent Measurements
- Measure at the same time of day, under the same conditions (morning, fasted, after bathroom is ideal)
- Use the same device/method every time
- Take 2-3 measurements and average them
- Track trends over months, not days
- Combine with progress photos and tape measurements for the full picture