📏 Body Fat % Estimator — Find out how much of your weight is muscle vs. fat.
cm
kg
📐 How to measure:
Neck: Below your larynx, tape horizontal.
Waist: At navel level (narrowest for women, belly button for men).
Hips (women only): Widest point around buttocks.
Neck: Below your larynx, tape horizontal.
Waist: At navel level (narrowest for women, belly button for men).
Hips (women only): Widest point around buttocks.
cm
cm
cm
25.4%
Average
Fat Mass
16.5 kg
Lean Mass
48.5 kg
For a 30‑year‑old female, a healthy body fat range is typically 21–33%.
This calculator uses the US Navy method. Results are estimates.
Author: Dr. Shirley Cheung | © theshirlshirl.com
Author: Dr. Shirley Cheung | © theshirlshirl.com
Why Body Fat % Matters More Than BMI
BMI doesn't distinguish between muscle and fat. Two people with the same BMI can have completely different health profiles. This calculator uses the US Navy method — a tape‑measure‑based formula validated against DEXA scans — to estimate your body fat percentage. You'll need a flexible measuring tape and about two minutes.
Once you have your number, the next question is where you carry that fat — belly fat carries different risks than hip fat. That's exactly what the Waist‑to‑Hip Ratio measures.
Disclaimer: This is an estimate. For a precise measurement, consider a DEXA scan or professional assessment.