US Navy Body Fat Calculator
Estimate your body fat percentage using the official circumference-based Navy method.
Male: 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76
Female: 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387
What is the Navy body fat percentage method?
The U.S. Navy body fat method estimates body fat using a few circumference measurements instead of expensive lab equipment. It is popular because it is quick, repeatable, and practical for home use. This calculator applies the official equations used for men and women and gives you a fast estimate of your current body composition.
How to measure correctly for accurate results
1) Height
Stand upright without shoes. Keep your back against a wall and measure from the floor to the top of your head.
2) Neck circumference
Measure just below the Adam’s apple (larynx). Keep the tape level and snug, but not tight.
3) Waist circumference
Measure at navel level, relaxed after a normal exhale. Do not suck in your stomach.
4) Hip circumference (women only)
Measure at the widest part of the hips/glutes with the tape level around the body.
Measurement tips
- Use a soft tape measure and mirror for alignment.
- Measure 2–3 times and average for better consistency.
- Track under the same conditions (time of day, hydration, meal timing).
- Focus on trends over weeks rather than one single reading.
How to interpret your result
Your calculated value is an estimate, not a diagnosis. A useful way to interpret body fat is by category:
- Men: Essential (2–5%), Athlete (6–13%), Fitness (14–17%), Average (18–24%), Obese (25%+)
- Women: Essential (10–13%), Athlete (14–20%), Fitness (21–24%), Average (25–31%), Obese (32%+)
If you entered body weight, this calculator also estimates fat mass and lean mass to help with planning nutrition and training.
Why people use a body fat percentage navy calculator
- Better than scale weight alone for tracking fat-loss progress.
- Useful for setting realistic physique and performance goals.
- Accessible and free compared with DEXA or hydrostatic testing.
- Simple enough for weekly or monthly check-ins.
Limitations to keep in mind
The Navy method is practical, but it is still an estimate. Hydration status, tape position, body shape, and measurement errors can change results. People with unusually high muscle mass or unique fat distribution may see more variation compared with lab methods.
For medical decisions, pair this estimate with professional guidance, blood markers, and a full health assessment.
How to lower body fat percentage safely
Nutrition basics
- Create a moderate calorie deficit (not extreme).
- Prioritize protein to preserve muscle while dieting.
- Eat high-fiber foods, vegetables, fruits, and minimally processed carbs.
- Stay consistent with meal timing and hydration.
Training basics
- Lift weights 2–5 times per week to maintain or build lean mass.
- Add cardio to increase energy expenditure and improve conditioning.
- Progress gradually and avoid all-or-nothing plans.
Recovery habits
- Sleep 7–9 hours most nights.
- Manage stress to support appetite and recovery control.
- Use weekly averages (weight, waist, body fat estimate) to judge progress.
Frequently asked questions
Is the Navy calculator accurate?
It is reasonably accurate for many adults when measurements are taken carefully, but still less precise than medical-grade scans.
How often should I check body fat?
Every 2–4 weeks is usually enough. Daily fluctuations can be misleading.
Can I use centimeters?
Yes. This calculator supports both imperial and metric units and converts automatically in the background.