How to use this calculator
- 1
Enter height and weight
These give your BMI — a quick population-level screening metric.
- 2
Measure your neck
Wrap a soft tape just below the larynx, sloping slightly downward to the front.
- 3
Measure your waist
Measure horizontally at the navel after a normal exhale, without sucking in.
- 4
Women: measure your hips
Measure at the widest point of the buttocks with feet together.
Real-world example
Priya, 165 cm and 62 kg, has a BMI of 22.8 (Normal). With a 32 cm neck, 72 cm waist and 96 cm hips, her estimated body fat is about 24% — in the healthy 'Fitness' range for women.
Features, accuracy & limitations
Formula: BMI = weight (kg) ÷ height (m)². Body fat uses the U.S. Navy formula based on log-transformed neck, waist, hip and height measurements.
Key features
- WHO BMI categories with a visual status bar
- Body fat % using a validated tape-measure method
- Gender-specific body fat ranges
- Metric and imperial height/weight
Limitations
- BMI cannot distinguish muscle from fat
- Navy method typically within ±3–4% of DEXA scans
- Measurement technique greatly affects accuracy
- Not validated for children, pregnancy or older adults with sarcopenia
Medical disclaimer: This calculator provides estimates for informational and educational purposes only. It is not a medical diagnosis and does not replace advice from a doctor, registered dietitian, or other qualified health professional. Consult a professional before making changes to your diet, exercise, or health routine — especially if you are pregnant, under 18, or have a medical condition.