Professional review pending. Body Fat Calculator has passed formula and automated QA checks, but no independently verified clinician is currently attributed. Content updated May 22, 2024. Review process

Body Fat Calculator

Estimate your body fat percentage with the U.S. Navy method. A more accurate indicator of health than BMI, our Body Fat Calculator helps you track your fitne...

Reviewed by CalculatorApp.me Health Team

Body Fat Calculator — Complete Guide

Navy circumference method, ACE healthy ranges, DEXA comparison, and evidence-based body composition interpretation.

14–24%

Healthy range (men)

21–31%

Healthy range (women)

3–5%

Essential fat (men)

10–13%

Essential fat (women)

What Is Body Fat Percentage?

Body fat percentage is the proportion of your total body weight that is composed of fat mass. It is a more clinically meaningful measure than BMI because it distinguishes between fat and lean tissue (muscle, bone, organs, water) — allowing far more accurate assessment of metabolic health risk and physical fitness.

Body fat is divided into two types: essential fat (required for physiological function — hormones, nervous system, organ insulation) and storage fat (energy reserve deposited in adipose tissue). Excessive storage fat — especially visceral fat around the abdominal organs — is strongly associated with insulin resistance, cardiovascular disease, and type 2 diabetes.

Unlike BMI, body fat percentage correctly identifies people who are "normal weight obese" (healthy BMI but high fat, low muscle) and "overfat" athletes (high BMI but lean). A 2016 study estimated that 30% of normal-BMI adults meet criteria for metabolic obesity when assessed by body fat percentage.

US Navy Circumference Method

Navy Formula — Men
Body Fat % = 86.010×log₁₀(waist − neck)
             − 70.041×log₁₀(height) + 36.76

Measurements needed:
  • Waist (at navel, cm)
  • Neck (below larynx, cm)
  • Height (cm)

Example (man, 180 cm, waist 90 cm, neck 38 cm):
Waist − Neck = 90 − 38 = 52 cm
log₁₀(52) = 1.716
log₁₀(180) = 2.255

BF% = 86.010(1.716) − 70.041(2.255) + 36.76
BF% = 147.58 − 157.94 + 36.76
BF% = 26.4%

Classification: Acceptable (borderline)

The US Navy method was developed by Hodgdon and Beckett (1984) for military fitness standards. Accuracy ±3–4% vs DEXA when circumferences are measured correctly.

Navy Formula — Women
Body Fat % = 163.205×log₁₀(waist + hip − neck)
             − 97.684×log₁₀(height) − 78.387

Measurements needed:
  • Waist (narrowest point, cm)
  • Hips (widest point, cm)
  • Neck (below larynx, cm)
  • Height (cm)

Example (woman, 165 cm, waist 75 cm,
  hips 97 cm, neck 33 cm):
Sum = 75 + 97 − 33 = 139 cm
log₁₀(139) = 2.143
log₁₀(165) = 2.217

BF% = 163.205(2.143) − 97.684(2.217) − 78.387
BF% = 349.83 − 216.58 − 78.387
BF% = 54.8%

Note: Women naturally carry higher fat;
classified by different ranges.

Women's formula uses waist+hip−neck because female fat distribution is more gynoid (hip/thigh). The hip measurement significantly improves accuracy for female body composition estimation.

Jackson–Pollock 3-Site (Skinfold)
Men — 3 Sites: Chest, Abdomen, Thigh
Body Density = 1.10938 − 0.0008267×S
             + 0.0000016×S² − 0.0002574×Age

Women — 3 Sites: Tricep, Suprailiac, Thigh
Body Density = 1.0994921 − 0.0009929×S
             + 0.0000023×S² − 0.0001392×Age

Where S = sum of 3 skinfolds (mm)

Body Fat % = (495 / Body Density) − 450
(Siri equation)

Example (Man, 35y, sum=55mm):
BD = 1.10938−0.0008267(55)+0.0000016(55²)−0.0002574(35)
BD = 1.10938−0.04547+0.00484−0.009009 = 1.0593
BF% = (495/1.0593) − 450 = 467.3 − 450 = 17.3%

Skinfold calipers measure subcutaneous fat at standardised sites. Accuracy ±3.5% vs DEXA when performed by trained technicians. Requires practice and consistent site location.

Waist-to-Height Ratio (WHtR)
WHtR = Waist Circumference ÷ Height
(same units — both cm or both inches)

Risk categories:
< 0.40  →  Extremely slim
0.40–0.49 →  Healthy / Slim
0.50–0.59 →  Overweight risk
≥ 0.60  →  Very high CVD risk

Simple rule: 'Keep waist < half your height'

Example 1: Waist 82 cm, Height 175 cm
  WHtR = 82 ÷ 175 = 0.47 → Healthy

Example 2: Waist 105 cm, Height 170 cm
  WHtR = 105 ÷ 170 = 0.62 → Very High Risk

WHtR is 2× better than BMI at predicting
cardiovascular events (Ashwell 2012)

Waist-to-height ratio is simple, requires no equation, and outperforms BMI at predicting diabetes and cardiovascular risk in most population studies. It is particularly useful when body fat testing is unavailable.

Healthy Body Fat Ranges by Age and Sex

Men — ACE Body Fat Categories

CategoryBody Fat %
Essential Fat2–5%
Athletes6–13%
Fitness14–17%
Acceptable18–24%
Obesity≥ 25%

Women — ACE Body Fat Categories

CategoryBody Fat %
Essential Fat10–13%
Athletes14–20%
Fitness21–24%
Acceptable25–31%
Obesity≥ 32%

Source: American Council on Exercise (ACE). Body fat % increases naturally with age even when weight stays constant — older adults may have higher fat % at the same BMI.

Body Fat Measurement Methods Compared

DEXA Scan

±1–2%

Cost: $50–200

Gold standard accuracy; measures regional fat and bone density

Requires medical facility; radiation exposure (low)

Hydrostatic Weighing

±1.5–2%

Cost: $30–75

Very accurate; well-validated method

Requires submersion in water tank; limited availability

BodPod (Air Displacement)

±2–3%

Cost: $30–50

No water submersion; quick (5 min)

Less available than DEXA; slightly less accurate

Skinfold Calipers

±3.5%

Cost: $5–20 (caliper)

Low cost; portable; quick

Technician skill-dependent; poor for obese individuals

US Navy Method

±3–4%

Cost: Free (tape measure)

No equipment needed; validated for military

Less accurate than lab methods; circumference errors compound

Bioelectrical Impedance (BIA)

±3–5%

Cost: $30–300

Fast; convenient; many home scales include it

Highly sensitive to hydration; can vary 4–6% within one day

Frequently Asked Questions

What body fat percentage is considered healthy for men?

According to the American Council on Exercise, healthy body fat for men is 14–17% (fitness) to 18–24% (acceptable). Athletes typically range 6–13%. Essential fat (minimum for survival) is 2–5% for men.

What body fat percentage is considered healthy for women?

Healthy body fat for women is 21–24% (fitness) to 25–31% (acceptable). Female athletes range 14–20%. Essential fat for women is 10–13%, significantly higher than men due to sex-hormone-related storage needs.

Can I reduce body fat without losing weight?

Yes — body recomposition (simultaneously losing fat and gaining muscle) is possible, particularly for beginners and those returning to training after a break. It requires adequate protein intake (≥1.6 g/kg), resistance training, and a small calorie deficit or maintenance calories.

Is visceral fat more dangerous than subcutaneous fat?

Yes. Visceral fat (intra-abdominal fat surrounding organs) secretes pro-inflammatory cytokines, promotes insulin resistance, and is strongly linked to metabolic syndrome, type 2 diabetes, and cardiovascular disease. Subcutaneous fat (under the skin) is metabolically less active and less dangerous.

References & Clinical Sources

  • Hodgdon JA, Beckett MB. Prediction of percent body fat for US Navy men and women. Naval Health Research Center, 1984.
  • American Council on Exercise. Percent Body Fat Norms for Men and Women. ACE, 2009.
  • Jackson AS, Pollock ML. Practical assessment of body composition. Physician Sportsmed. 1985;13(5):76–90.
  • Ashwell M, et al. Waist-to-height ratio is more predictive of years of life lost than BMI. PLoS ONE. 2014;9(9):e103483.
  • Romero-Corral A, et al. Accuracy of BMI in diagnosing obesity in the adult general population. Int J Obes. 2008;32(6):959–66.

Methodology, sources & limitations

This calculator uses a published formula and the values entered in the calculator to generate the result.

Formula
BF% = 495 / (1.0324 - 0.19077×log10(waist-neck) + 0.15456×log10(height)) - 450
Jurisdiction & units
Intended for US, IN, EU, GB, Global. Supports both units where applicable.
Assumptions & limitations
Results are screening or educational estimates based on the inputs you provide. They do not diagnose, treat, or replace advice from a qualified clinician.
Review status
Formula and automated QA completed May 22, 2024; independent professional review is pending. Next scheduled review: August 22, 2026.

Validation sources

  • U.S. Navy Physical Readiness Program
  • ACSM Body Composition Guidelines

Body Fat Calculator — Answer & Method

Estimate body fat percentage using the U.S. Navy circumference method.

Formula: U.S. Navy Body Fat Formula (Male)

BF% = 495 / (1.0324 - 0.19077×log10(waist-neck) + 0.15456×log10(height)) - 450

waist = Waist circumference (cm)
neck = Neck circumference (cm)
height = Height (cm)

Example Calculation

A male with 85 cm waist, 38 cm neck, and 178 cm height has approximately 17.7% body fat.

Important limitation

This is an educational estimate, not a diagnosis or a substitute for professional medical advice.

Key Facts

  • The U.S. Navy method uses circumference measurements to estimate body fat percentage.
  • Essential fat is 3-5% for men and 10-13% for women.
  • Athletes typically have 6-13% body fat (men) or 14-20% (women).

Sources & Validation

U.S. Navy Physical Readiness ProgramACSM Body Composition Guidelines

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Deterministic: YesAI-Generated Numbers: NoVerified: 2026-02-12

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