Body Fat Percentage Calculator

Name: Body Fat Percentage Calculator
Author: CalculatorBolt

Calculate your body fat percentage using the U.S. Navy or YMCA method. Enter your weight, measurements (waist, hip, neck), height, and sex to estimate your BF%, body fat mass, and lean body mass. Includes fitness classification. Informational only—consult a healthcare professional for accurate assessment. Explore more tools on free calculators on CalculatorBolt.

Calculator

Calculation Method

Sex

Used for calculation accuracy

Age (years)

For classification

Units

Weight (kg)

Height (cm)

Height (feet)

Height (inches)

Neck (cm)

At narrowest point

Waist (cm)

At navel level

Body Fat %

Fat Mass

Lean Mass

Classification

Import JSON

How it works

U.S. Navy Method (Male): BF% = (495 / (1.0324 - 0.19077 × log₁₀(Waist - Neck) + 0.15456 × log₁₀(Height))) - 450

U.S. Navy Method (Female): BF% = (495 / (1.29579 - 0.35004 × log₁₀(Waist + Hip - Neck) + 0.22100 × log₁₀(Height))) - 450

YMCA Method: Simplified circumference-based formula using weight and measurements.

We calculate body fat percentage, body fat mass (Weight × BF%), lean body mass (Weight - Fat Mass), and provide a fitness classification based on standard ranges.

Inputs explained

Sex: Required for accurate calculation as men and women have different body fat distributions.
Age: Used for classification purposes (essential, athlete, fitness, average, obese).
Weight: Your total body weight in kg or lbs.
Height: Your height in cm or feet/inches.
Neck: Circumference at the narrowest point below the larynx.
Waist: Circumference at navel level, measured at the end of a normal exhale.
Hip (females only for U.S. Navy): Circumference at the widest point of the hips.

Example

Male, U.S. Navy Method:

Weight: 70 kg
Height: 175 cm
Neck: 38 cm
Waist: 85 cm

Results:

Body Fat %: ~18.5%
Body Fat Mass: ~12.95 kg (28.5 lbs)
Lean Body Mass: ~57.05 kg (125.8 lbs)
Classification: Average/Fitness

Tips & notes

Use a flexible tape measure for accurate circumference measurements.
Take measurements at the same time of day, preferably in the morning.
The U.S. Navy method is considered accurate for most people and is used in military fitness assessments.
Keep the tape parallel to the floor and snug but not compressing the skin.
For best results, have someone else take your measurements.
Body fat percentage can fluctuate 1-2% due to hydration and meal timing.

Body Fat Classification Ranges

Classification	Men	Women
Essential Fat	2-5%	10-13%
Athletes	6-13%	14-20%
Fitness	14-17%	21-24%
Average	18-24%	25-31%
Obese	25%+	32%+

FAQs

It varies by age and sex. For men, 10-20% is considered average to fitness level; for women, 20-30% is average to fitness. Athletes typically have lower percentages, while essential fat is 2-5% for men and 10-13% for women.

Use calipers, DEXA scans, or bioimpedance scales for more accurate measurements. This calculator estimates body fat from circumference measurements using the U.S. Navy or YMCA method.

The U.S. Navy method is often used for fitness assessments and is considered more accurate for most people. The YMCA method is simpler but may be less accurate for some body types.

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Circumference-based methods like U.S. Navy and YMCA are estimates and can vary by 3-4% compared to more accurate methods like DEXA scans or hydrostatic weighing.

For the U.S. Navy method, measure at the narrowest point of your waist, typically at navel level. Keep the tape parallel to the floor and measure at the end of a normal exhale.

Sustainable fat loss is typically 0.5-1% body fat per month. Rapid changes usually involve water weight or muscle loss rather than fat loss.

Lean body mass is your total body weight minus your body fat mass. It includes muscle, bone, organs, and water—everything except fat tissue.

Disclaimer

Informational estimate only. Body fat percentage can vary based on measurement method and individual factors. This calculator provides estimates based on circumference measurements and may differ from more accurate methods like DEXA scans. Consult a healthcare professional for accurate assessment and personalized health advice.