Body Fat Percentage Calculator

Estimate your body fat percentage using the US Navy method (tape measurements) and the BMI method. Get your fat mass, lean mass, and fitness category.

Unit System

Biological Sex

Height (cm)

Weight (kg)

Waist circumference (cm)

measure at navel

Neck circumference (cm)

Body Fat Results

Fill in your measurements and click Calculate.

Body Fat Percentage Categories

Men

Category	Body Fat %
Essential Fat	2–5%
Athletes	6–13%
Fitness	14–17%
Average	18–24%
Obese	25%+

Women

Category	Body Fat %
Essential Fat	10–13%
Athletes	14–20%
Fitness	21–24%
Average	25–31%
Obese	32%+

Frequently Asked Questions

The US Navy formula has a margin of error of ±3–4% compared to DEXA scanning. It is one of the most accurate field methods available without equipment. Accuracy depends on careful tape measurement — measure at the same time of day and take 3 readings to average.

For men, 14–17% is generally considered fit, and 18–24% is healthy average. For women, 21–24% is fit and 25–31% is average. Essential fat (the minimum for organ function) is 2–5% for men and 10–13% for women. Going below essential fat is dangerous.

BMI doesn't distinguish between fat mass and lean mass. A muscular athlete can have an "obese" BMI while having low body fat. Conversely, a "normal" BMI person can have high body fat (skinny-fat). Body fat percentage directly measures body composition and is a better indicator of health risk and fitness.

Essential fat is the minimum amount required for normal physiological functioning — protecting organs, insulating nerves, regulating hormones. It represents approximately 2–5% in men and 10–13% in women. Storage fat is the additional fat used as an energy reserve. Excess storage fat, particularly abdominal fat, increases risk of metabolic disease.

ACE classifications — Men: Essential fat 2–5%, Athletes 6–13%, Fitness 14–17%, Acceptable 18–24%, Obese 25%+. Women: Essential fat 10–13%, Athletes 14–20%, Fitness 21–24%, Acceptable 25–31%, Obese 32%+.

The US Navy formula has a typical margin of error of ±3–4 percentage points. A DEXA scan is considered the gold standard with an accuracy of ±1–2%, and also distinguishes bone density from fat and lean tissue. For most people, the Navy formula is a practical and reasonably accurate option without any equipment.

Reducing body fat requires a sustained calorie deficit. The most effective approach combines a modest calorie deficit (300–500 kcal/day below TDEE), high protein intake (1.6–2.2 g/kg), and resistance training. Realistic progress is 0.5–1% body fat reduction per month.

Subcutaneous fat lies just beneath the skin and is the fat you can pinch. Visceral fat is stored deep in the abdominal cavity, surrounding internal organs. Visceral fat is highly metabolically active and releases inflammatory compounds that increase risk of type 2 diabetes, cardiovascular disease, and certain cancers. Waist circumference above 94 cm for men and 80 cm for women is a risk warning.

Common methods ranked by accuracy: DEXA scan (±1–2%); Hydrostatic weighing (±1.5%); Bod Pod (±2–3%); US Navy formula (±3–4%); Skinfold calipers (±3–5%); Bioelectrical impedance (BIA) (±3–8%). Smart scales are convenient but inconsistent — use them to track trends rather than absolute values.

Yes — this is sometimes called "metabolically obese normal weight." A person can have a normal BMI yet carry dangerous levels of visceral fat, particularly around the abdomen. Waist circumference is a better proxy for visceral fat risk than BMI alone. Aerobic exercise and calorie reduction are the most effective interventions.

About This Body Fat Calculator

This free body fat percentage calculator estimates your body fat using the US Navy method, which requires measurements of height, neck, and waist (and hips for women). No body fat scale or DEXA scan needed — just a flexible tape measure.

When to use this calculator

Tracking fat loss progress alongside scale weight
Comparing body composition before and after a training programme
Setting a body fat percentage goal in the athletic or fitness range
Estimating body fat without specialist equipment

Standards & References

In-depth guides and technical articles.

View all →

Health Jul 27, 2026

The Scale Hasn't Moved in Six Weeks — Reading Recomposition

A flat scale weight can hide meaningful changes in body composition. Here's which measurements actually reveal recomposition and how to interpret them over time.

Health Jun 23, 2026

Why Skinfold Calipers Underestimate Body Fat in Some Populations — The Regression Equation Backstory

Skinfold caliper sites aren't arbitrary — they're the locations where subcutaneous fat thickness best predicted total body fat in the 1970s regression equation development studies using hydrostatic weighing as the reference. Here's why the Jackson-Pollock and Durnin-Womersley equations underestimate body fat in East Asian populations, caliper inter-rater reliability (±3-5% between trained technicians), and why calipers are better for tracking changes than determining absolute percentage.

Health Jun 18, 2026

Why Women Need 3× More Essential Body Fat Than Men — and What Different Fat Types Actually Do

Women's essential fat minimum (10-13%) is so much higher than men's (3-5%) not because of reserves or fitness level, but because the sex-specific fat deposits involved in reproductive hormone synthesis and neurological function require it. Here's the essential vs storage fat distinction, why visceral fat location matters more than total body fat percentage for metabolic health, why "athletic" body fat isn't necessarily optimal for non-athletes, and the body recomposition tracking paradox.

Health Jun 14, 2026

Body Fat Percentage Tracking: Why Your Daily Reading Swings 3% and What to Actually Pay Attention To

A body-fat reading that swings 2-3 percentage points overnight isn't your body composition changing that fast — actual fat changes occur over weeks, while day-to-day swings are almost entirely hydration, meal timing, and measurement-method noise. Here's why a consistent measurement protocol matters more than any single reading's accuracy, why trend lines over weeks reveal the real signal, and why switching measurement methods means starting a new trend, not continuing the old one.

Health Jun 13, 2026

DEXA, BIA, Calipers, and Hydrostatic Weighing: How Body Fat Measurement Methods Compare

DEXA, hydrostatic weighing, BIA scales, and skinfold calipers can give different body fat percentages for the same person on the same day. Here's what each method actually measures, why BIA scales are so sensitive to hydration, and how to choose between accuracy and practicality for tracking your own body composition.