Body Fat Calculator
Overview
This free Body Fat Calculator estimates your body fat percentage using the US Navy method, BMI-based formula, and optional skinfold measurements. Enter your height, weight, waist, neck, and (for women) hip measurements to calculate body fat %, fat mass, and lean body mass. The Navy method is one of the most accessible and reliable estimation techniques, while the BMI and Covert Bailey formulas provide additional reference points. For fitness and training use, you can enable 3-site or 7-site skinfold measurements for more detailed accuracy. Everything runs instantly in your browser, with no data stored or sent anywhere.
About
About Body Fat Calculator
The US Navy method estimates body fat based on the relationship between circumference measurements and body density. It is widely considered a reliable field formula for everyday use. The BMI-based estimate applies a statistical equation using height, weight, age, and sex. For highly active individuals or those with access to calipers, the Jackson-Pollock skinfold method provides a more accurate way to estimate body density by measuring fat at multiple anatomical sites. All methods used in this calculator rely on validated equations and provide reasonable estimates for general health tracking, though they cannot replace medical or DEXA evaluations.
Features:
- US Navy method – reliable circumference-based estimation
- BMI-based formula – quick estimate using height and weight
- Covert Bailey method – alternative calculation approach
- Jackson-Pollock skinfold – 3-site and 7-site options for precision
- Body composition breakdown – fat mass and lean body mass
- Category classification – essential, athletic, fit, average, obese
- Metric and imperial units – cm/kg or in/lb support
- Method comparison – view results from multiple formulas
- 100% client-side – no data storage or transmission
- No registration required – instant results
FAQ
How accurate is the US Navy body fat calculator?
It's generally reliable for population averages but less precise than DEXA or hydrostatic testing. The Navy method provides reasonable estimates for everyday health tracking.
Which method should I use?
The Navy method provides solid everyday estimates. Skinfold is more accurate if measured correctly with proper calipers. BMI-based estimates are quick but less precise for muscular individuals.
Do I need to measure hips?
Only for females using the US Navy formula. Males do not need hip measurements for the Navy method.
Why do BMI estimates differ from Navy results?
BMI does not account for body composition and may overestimate fat for muscular individuals or underestimate for sedentary people. The Navy method uses circumference measurements which better reflect body composition.
Is this safe for health decisions?
Use results as general estimates for tracking progress. Consult a medical professional when making significant health or fitness decisions. These calculations are informational only.
What are body fat categories?
Categories vary by sex. For men: Essential (0-13%), Athletic (13-17%), Fit (17-21%), Average (21-26%), Obese (26%+). For women: Essential (0-20%), Athletic (20-24%), Fit (24-31%), Average (31-36%), Obese (36%+).
Can I use this for tracking fitness progress?
Yes! Track your body fat percentage over time to monitor body composition changes during training. Use the same method consistently for accurate comparisons.
What is lean body mass?
Lean body mass is your total body weight minus fat mass. It includes muscle, bone, organs, and water. Building lean mass while reducing fat is a common fitness goal.