Body Fat (YMCA Method) Calculator

Work out body fat (ymca method) instantly with clear inputs, formula shown and shareable results.

About Body Fat (YMCA Method) Calculator

The YMCA method needs only a waist measurement and body weight, working in imperial units internally: fat pounds = 4.15 x waist inches - 0.082 x weight pounds - 98.42 for men. A 90 cm waist at 80 kg gives about 22% fat. It is the least equipment-hungry estimate and correspondingly the roughest, with errors of 4-5 percentage points.

Formulas

YMCA formula, men

fat lb = 4.15 x waist(in) - 0.082 x weight(lb) - 98.42

YMCA formula, women

fat lb = 4.15 x waist(in) - 0.082 x weight(lb) - 76.76

Worked example

With the default values below, Body Fat (YMCA Method) Calculator returns Estimated Body Fat of 19.37%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Waist circumference at the navelminimum 30 cm: 90 cm
Body weightminimum 1 kg: 80 kg
Sexone of Male, Female: Male

Results

Estimated Body Fat: 19.37%
Fat Mass: 15.50 kg
Lean Mass: 64.50 kg
Category: Average

Step by step

1Values used
2YMCA formula, men
3YMCA formula, women
4Estimated Body Fat= 19.37
5Fat Mass= 15.50 kg
6Lean Mass= 64.50 kg
7Category= Average

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.

Frequently Asked Questions

Why is only the waist used?

Because abdominal circumference correlates most strongly with total body fat in sedentary populations, which is who the equation was fitted on.

Who does this method suit least?

Muscular people, whose weight term inflates the estimate, and anyone with a slim waist but high peripheral fat.