Health & Fitness
Estimate body fat percentage with the U.S. Navy circumference method using height, neck, waist, and hip measurements.
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Choose the sex used by the Navy circumference formula.
Select metric or imperial units and enter height, neck, and waist measurements.
If using the female formula, enter hip circumference at the widest point.
Add age only as optional context; it is not used in the Navy formula.
Calculate the estimate and review the general interpretation band.
Re-measure if the result looks unusual, and use the result as general information only.
The Body Fat Percentage Calculator estimates body fat using the U.S. Navy circumference method. It uses height, neck, waist, and, for the female formula, hip circumference to create a quick body composition estimate without scales, calipers, or lab equipment.
The Navy method is a circumference-based equation. This tool accepts metric or imperial measurements, converts metric values to inches internally, and applies the standard Navy formulas consistently. The result is rounded to one decimal place and shown with a broad educational interpretation band such as essential range, athletic range, fitness range, average range, or higher range.
This estimate can be useful for general fitness tracking, wellness check-ins, and comparing changes over time when measurements are taken consistently. It is not a diagnosis and should not be treated as a complete health assessment. Body fat percentage varies by sex, age, athletic background, hydration, posture, tape placement, and measurement method.
Accuracy depends heavily on careful measuring. Use a flexible tape, keep it level, measure waist at the navel level for this calculator, measure neck just below the larynx area, and measure hips at the widest point when using the female formula. The tape should be snug but not tight. Repeating measurements can help reduce one-off errors.
The Navy circumference method is convenient, but it is not the same as DEXA, hydrostatic weighing, skinfold calipers, smart scales, or a professional body composition assessment. Each method has limitations, and results from different methods may not match exactly.
This calculator provides an estimate for general information only. It is not medical advice, diagnosis, or a substitute for guidance from a qualified healthcare professional. Consult a qualified healthcare professional for personal health decisions, especially if you have a medical condition, are pregnant, are a teenager, or have concerns about body image, diet, or exercise.
Estimate body fat percentage using a tape-measure-based Navy method.
Track general body composition changes over time with consistent measurements.
Compare a circumference-based estimate with BMI, smart scale readings, or other methods carefully.
Use body fat percentage as one general wellness metric alongside weight, strength, energy, and habits.
Plan a fitness check-in without treating the result as a diagnosis or medical assessment.
Measure at the same time of day when possible for more consistent comparisons.
Use a flexible tape and keep it snug, level, and not tight against the skin.
Use the same unit system for all measurements and avoid mixing inches and centimeters.
Measure waist at the navel level for this calculator so repeated checks are comparable.
Repeat measurements if the estimate changes sharply or looks unusual.
Use the result as one general signal, not as the only measure of health or fitness progress.
Do not pull the measuring tape too tight or leave it too loose.
Do not measure the waist, neck, or hips at inconsistent points each time.
Do not mix metric and imperial measurements in the same calculation.
Do not treat the estimate as a diagnosis, medical result, or guarantee of health status.
Do not compare Navy-method results directly with DEXA, skinfold, or smart-scale results without context.
Calculate body mass index from height and weight, then view the general BMI category for an educational health reference.
Estimate basal metabolic rate from age, height, weight, and sex to understand approximate resting calorie needs.
Estimate daily water intake from body weight, activity, climate, and lifestyle factors as a simple hydration planning reference.
Estimate maintenance calories, deficit targets, or surplus needs using activity level, body details, and fitness goal inputs.
Height
Measure height without shoes, standing tall with relaxed posture.
Neck
Measure just below the larynx area with the tape level and snug, not tight.
Waist
Use the navel level for this calculator and keep the tape horizontal.
Hip
For female calculation, measure around the widest point of the hips.
Use a flexible tape, keep it snug but not tight, and use the same unit system for every measurement.
Metric values are converted to inches, then the standard U.S. Navy circumference formula is applied with Math.log10.
Body fat percentage and BMI answer different questions. You can also review the BMI Calculator, but neither method is a full health assessment.