Body Fat Calculator

Created by Lead Calculators, Modified on Mon, 29 Sep, 2025 at 12:56 PM by Lead Calculators

The Body Fat Calculator estimates the percentage of body fat based on your measurements. By entering key information such as weight, height, and other relevant metrics, the calculator provides an indication of your body composition and overall fitness level.

The details that users need to enter in the calculator are as follows:

Biological gender
Age range
Height (ft. in.)
Weight range
Waist measurement (inches)
Neck measurement (inches)
Hips measurement (for women only)

These details are then computed by the calculator using the following formulas:

For men:

Body Fat Percentage=86.010×log10(Waist−Neck)−70.041×log10(Height)+36.76

For women:

Body Fat Percentage=163.205×log10(Waist+Hips−Neck)−97.684×log10(Height)−78.387

Score Calculation

Different scores are interpreted as follows:

Age	Male	Female	Scoring Interpretation
18-21	Less than or equal to 22%	Less than or equal to 33%	Within a healthy body fat range
18-21	Greater than 22%	Greater than 33%	Above the recommended body fat range
22-29	Less than or equal to 23%	Less than or equal to 34%	Within a healthy body fat range
22-29	Greater than 23%	Greater than 34%	Above the recommended body fat range
30-39	Less than or equal to 24%	Less than or equal to 35%	Within a healthy body fat range
30-39	Greater than 24%	Greater than 35%	Above the recommended body fat range
40 and above	Less than or equal to 26%	Less than or equal to 36%	Within a healthy body fat range
40 and above	Greater than 26%	Greater than 36%	Above the recommended body fat range

Default Email Responses

There are two default email responses depending on the calculated score. You can customize the email content when setting up your BMI calculator to match your messaging better.

Within a healthy body fat range

Your body fat percentage is within the recommended range for your age and sex. This suggests a healthy balance between lean mass and body fat, which supports better metabolic function, hormone regulation, and overall wellness. Keep up your habits with consistent physical activity, a nutrient-dense diet, and regular self-care.

Above the recommended body fat range

Your body fat percentage is currently above the suggested range for optimal health. This doesn’t define your fitness, but it can be a helpful signal to evaluate your current nutrition, exercise, and recovery habits. Consider speaking with a wellness professional to explore strategies for building lean muscle and supporting long-term health goals.

To edit the copies of each email response, please see our help article on creating a calculator and editing the email templates.