Your Body & Measurement Details
This calculator uses the US Navy body fat formula. Please take measurements correctly for better estimation.
Measure at narrowest point / navel level, relaxed breath out
Below larynx, keep head neutral
Widest part of hips / buttocks
Important Health & Medical Disclaimer
This Body Fat Percentage Calculator uses the US Navy formula for estimation purposes only. Results are approximations and may contain significant error due to measurement technique, individual body composition, bone structure and other factors. This tool is not a medical diagnostic device, nor does it replace professional health assessment, DXA scans or advice from a physician or certified health professional. Do not use these estimates to make medical decisions.
About the US Navy Body Fat Formula
The US Navy formula estimates body fat using simple circumference measurements (waist, neck, hip for women), height and weight. It is a widely‑used field‑friendly estimation method but is less accurate than DXA scan, hydrostatic weighing or air displacement plethysmography.
ACE (American Council on Exercise) provides general population body‑fat reference ranges shown in this calculator.
Body Fat Calculation FAQ
Why is this only an estimate?
Circumference‑based formulas cannot account for bone density, muscle distribution, water retention, posture and measurement errors. Even DXA scans have small margins of error.
What is the difference between BMI and body fat percentage?
BMI only uses height and weight and cannot distinguish muscle vs fat mass. Two people with identical BMI can have vastly different body fat levels (e.g. weight‑trained athlete vs sedentary person).
Can I change my body fat quickly?
Healthy rate of fat loss is roughly 0.5–1% of body weight per week via balanced nutrition, resistance training, cardio and adequate recovery. Rapid extreme fat loss carries health risks.
Are very low body fat percentages healthy long‑term?
Essential fat levels are required for hormone function, immune health and organ protection. Sustained extremely low body fat may cause hormonal disruption, fatigue and health complications.