Body Fat Calculator

Estimate body fat percentage using the U.S. Navy method and BMI-based calculations. Compare fat mass vs lean mass, view your body composition category, and track fitness progress. Requires waist, neck, and hip measurements. Includes body fat category charts for men and women, plus healthy body fat ranges by age.

Measure just below the Adam's apple.

Measure at the navel.

Body Fat
18%
Fitness

U.S. Navy Method

Target
16%
1.4 kg fat mass to lose

ACE Fitness range target

Body Fat Breakdown

Detailed breakdown of your body fat metrics and composition

Body Composition
Total: 72 kg
18%
82%
Fat12.9 kg
Lean59.1 kg

Estimates based on population formulas. Navy method uses body measurements and is generally more accurate than BMI-based estimates.

Body Fat Category Table

ACE body fat ranges by category for men (Navy method)

ACE (American Council on Exercise) body fat percentage ranges by category for men (Navy method).

Method Comparison

We estimate body fat using both the Navy and BMI methods.

Navy method
18%

Uses neck, waist, and hip (for women) measurements along with height to estimate body fat.

BMI method
20%

Based on BMI and age. Quick to calculate, but less personalized for muscular or very lean bodies.

For very muscular or very lean individuals, measurement-based methods or professional tools may give better estimates than BMI-based formulas.

Visual Comparison

See where your body fat percentage falls relative to the healthy range. (Navy method)

Healthy Range
Men: 8–19%
18
0
8
19
100
Your Body Fat: 18%
Within healthy range

The healthy range shown is based on ACE (American Council on Exercise) guidelines. Body fat percentage can vary with age, muscle mass, and fitness goals. For athletes or those with high muscle mass, body fat may naturally fall outside these ranges.

What is body fat percentage?

Essential vs. storage fat and why the ratio matters

Body fat percentage is the share of your total weight made up of fat tissue. Everyone needs some fat for hormone production, organ protection, and healthy cell function—this is called essential fat. Storage fat is the extra reserve your body keeps in fat cells and around organs for later use.

Why body fat % can be more useful than weight or BMI

How body composition adds context beyond the scale

The scale can only tell you total weight—it cannot show how much is muscle versus fat. BMI is a simple height/weight ratio and treats all weight the same, which can under-rate muscular people or over-rate very lean individuals. Body fat % adds context by showing what portion of your weight is fat mass versus lean mass.

How this calculator estimates body fat

Navy method and BMI method formulas explained

Navy method: Uses neck, waist, and (for women) hip measurements plus height to estimate body fat. It was popularized by the U.S. Navy for quick field assessments.
Men
BF% = 86.010 × log₁₀(waist - neck) - 70.041 × log₁₀(height) + 36.76
Women
BF% = 163.205 × log₁₀(waist + hip - neck) - 97.684 × log₁₀(height) - 78.387
All measurements in inches
BMI method: Uses BMI and age to produce a quick estimate. It is simple and works with limited inputs but is less personalized for very lean or very muscular bodies.
Men
BF% = 1.20 × BMI + 0.23 × age - 16.2
Women
BF% = 1.20 × BMI + 0.23 × age - 5.4

Healthy ranges and when to talk to a doctor

Gender-specific ranges and warning signs to watch for

Healthy ranges differ for men and women and shift with age. Very low body fat can disrupt hormones and energy; very high body fat can increase risks for heart disease, type 2 diabetes, and joint stress. If your numbers are far outside the healthy range or you have symptoms, speak with a healthcare professional for individualized guidance.

Frequently Asked Questions

Common questions about body fat percentage and measurement methods

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