Body Fat Percentage Calculator
Estimate your body fat percentage using the YMCA method, based only on your body weight and waist circumference.
Measure at the navel, standing relaxed.
Estimated Body Fat (YMCA Method)
16.3%
Fitness
Body Fat Percentage Calculator — YMCA Method
This calculator estimates body fat percentage using the YMCA method, a formula developed for use in YMCA fitness assessments that needs only two measurements — body weight and waist circumference. It's a different, quicker estimation approach than the tape-measure US Navy method (which factors in neck, waist, height, and hip), making it a useful alternative when you want a fast estimate without measuring your neck or hips.
How the YMCA Formula Works
- Select your gender and preferred unit (metric or US).
- Enter your body weight.
- Enter your waist circumference, measured at the navel while standing relaxed.
- The formula converts your inputs to pounds and inches internally, then applies:
Men: ((-98.42 + 4.15 × waist) − 0.082 × weight) / weight × 100,Women: ((-76.76 + 4.15 × waist) − 0.082 × weight) / weight × 100.
Example
A man weighing 180 lbs with a 34-inch waist gets an estimated body fat percentage in the "Average" range using the YMCA formula above.
Common Use Cases
- Getting a fast body fat estimate with just a scale and a tape measure around the waist.
- Cross-checking results against other estimation methods, like the Navy tape-measure method.
- Tracking body composition trends over time without special equipment.
FAQs
How is this different from your other body fat calculator?
This tool uses the YMCA method, which only requires body weight and waist circumference. Our separate Body Fat Calculator uses the US Navy tape-measure method, which requires neck, waist, height, and (for women) hip measurements. The two formulas can give slightly different results since they use different inputs and statistical models.
How accurate is the YMCA body fat method?
It's a reasonable estimate for the general population but, like all circumference-based formulas, it is not as precise as lab methods such as DEXA scans or hydrostatic weighing. It tends to be less accurate for very muscular or very lean individuals. Use it to track trends over weeks and months rather than treating any single reading as an exact number. This tool is for general fitness information only and is not a substitute for professional medical or clinical body composition testing.
What do I need to measure for this calculator?
Just your body weight and your waist circumference at the navel — no neck or hip measurement is required for the YMCA method, unlike the Navy tape-measure method.