Body Fat Calculator
How it worksEstimate body fat % with the US Navy method
Free body fat percentage calculator using the US Navy circumference method. Enter height, neck, waist (and hips for women) for an educational estimate — not a lab measurement.
Your details
Estimated body fat %
Tape measurements in centimetres. Measure snug, not compressing soft tissue.
Body fat
16.2 %
Category: Fitness
About this Body fat % calculator
Body fat percentage estimates how much of your mass is fat versus lean tissue. It can add context that weight and BMI alone miss — especially if you lift.
The US Navy method uses tape measurements and a log formula. It is popular because it needs no calipers or DEXA, but results can be off by several percentage points.
Measure consistently (same time of day, relaxed posture, tape snug but not compressing soft tissue) if you want to track trends.
A body fat calculator using the US Navy circumference method estimates BF% from height, neck, waist, and (for women) hips — no calipers required. Habbeat walks you through the inputs and category bands for education.
People searching “body fat percentage calculator” or “US Navy method” want a home-friendly alternative to BMI. We emphasise measurement technique and trends over absolute precision.
Combine BF% estimates with Habbeat progress photos and weekly summaries — visual and habit trends often tell a clearer story than one percentage.
How to use this free tool
- Set sex and height in Your details.
- Add neck and waist (plus hips if female) in the calculator.
- We apply the Navy log formula and map the result to common adult category bands.
Worked examples
- Example: Consistent weekly tape measurements matter more than one “perfect” reading.
- Example: If weight is flat but waist drops, composition may be improving even when the scale stalls.
- Example: Very muscular or very lean physiques can see larger Navy-method error — treat BF% as a trend tool.
Practical tips
- Measure neck just below the larynx; waist at the navel (or narrowest point — stay consistent).
- For women, hips are the widest point of the buttocks.
- Use trends over weeks, not a single reading, to judge progress.
Limitations & caveats
- Navy circumference estimates can miss by several points vs DEXA.
- Tape placement errors dominate results — stay consistent.
- Essential fat is required; lower is not always healthier.
Frequently asked questions
How accurate is the Navy method?
It is a field estimate. Compared with DEXA or Bod Pod it can miss by a few points, especially at extremes of body composition. Great for trends; imperfect for absolute truth.
Is lower always better?
No. Essential fat is required for health. Very low levels — especially for women — can disrupt hormones and performance. Aim for a sustainable range with a professional if unsure.
Why do I need hip measurement?
The female Navy equation includes hips. The male equation uses waist and neck only.
What is a healthy body fat percentage?
Ranges vary by sex and age. Athletic and essential-fat floors differ; very low levels can harm hormones and performance. Use charts as orientation, not a dare.
Morning or evening measurements?
Pick one routine and stick to it. Morning after the bathroom, before food, is a common standard for trend tracking.
Is DEXA worth it?
DEXA or Bod Pod can be more accurate for a snapshot. For weekly habits, cheap consistent tapes plus photos are often enough.
Related free calculators
BMI Calculator
Check your body mass index from height and weight
Ideal Weight Calculator
Devine formula plus a healthy BMI weight range
Macro & Nutrient Calculator
Protein, carbs, fat, fiber, and micronutrient references
Looking for something else? Browse all Habbeat fitness tools, build a diet plan, or explore Habbeat features.
All toolsDisclaimer: These tools provide general estimates only. They are not medical advice. For health conditions, pregnancy, or personalised nutrition, speak with a qualified professional.