Body Fat Calculator
Use this free body fat calculator to estimate your body fat percentage using your body measurements. Unlike BMI, which only considers height and weight, body fat percentage tells you how much of your body is actually fat — giving you a far more accurate picture of your health and fitness. Enter your measurements below for an instant result using the US Navy formula.
Body Fat Calculator
How to Use the Body Fat Calculator
- Select your sex
- Enter your height (cm or inches)
- Enter your waist circumference (measured at the navel)
- Enter your neck circumference (measured just below the larynx)
- Women only: Enter your hip circumference (measured at the widest point)
- Click Calculate for your body fat percentage and category
What Is Body Fat Percentage?
Body fat percentage is the proportion of your total body weight made up of fat tissue. It distinguishes between fat mass (adipose tissue) and lean mass — which includes muscle, bone, water, and organs. Two people can have exactly the same BMI but very different body fat percentages: a muscular athlete and a sedentary person of the same height and weight will look completely different and have very different health profiles.
This is why body fat percentage is considered a superior health metric to BMI for most people — particularly those who exercise regularly. Pair this calculator with our BMI Calculator and Ideal Weight Calculator for a complete body composition overview.
Healthy Body Fat Percentage Ranges
| Category | Men | Women | Health Implication |
|---|---|---|---|
| Essential Fat | 2–5% | 10–13% | Minimum needed for organ function — not a target |
| Athletic | 6–13% | 14–20% | High performance, very lean — typical of competitive athletes |
| Fitness | 14–17% | 21–24% | Lean and healthy — ideal for active adults |
| Acceptable | 18–24% | 25–31% | Healthy range for general population |
| Overweight | 25–29% | 32–36% | Elevated health risk — improvement recommended |
| Obese | 30%+ | 37%+ | High health risk — medical guidance recommended |
How the US Navy Body Fat Formula Works
This calculator uses the US Navy circumference method, one of the most widely validated non-invasive body fat estimation techniques. It was developed by Hodgdon and Beckett in 1984 and is used by the US military for fitness assessments.
The formula for men uses waist and neck measurements:
Body Fat % = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76
The formula for women adds hip measurement:
Body Fat % = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387
Accuracy is typically within ±3–4% compared to DEXA scan results for most people — making it one of the most accurate methods that doesn’t require specialist equipment.
Body Fat Percentage vs BMI — A Direct Comparison
| Example Person | Height | Weight | BMI | BMI Category | Body Fat % | Body Fat Category |
|---|---|---|---|---|---|---|
| Male endurance runner | 5’10” | 72 kg | 23.1 | Healthy | 8% | Athletic |
| Male powerlifter | 5’10” | 95 kg | 30.5 | Obese | 14% | Fitness |
| Female office worker | 5’5″ | 65 kg | 24.0 | Healthy | 33% | Overweight |
| Female recreational gym-goer | 5’5″ | 65 kg | 24.0 | Healthy | 23% | Fitness |
The table above shows why BMI alone can be misleading. The powerlifter’s BMI labels him as “obese” despite having a healthy body fat percentage. Two women of identical height and weight have dramatically different body fat percentages depending on their activity level and muscle mass — but BMI treats them identically.
How to Reduce Body Fat Percentage
- Calorie deficit: Losing fat requires consuming fewer calories than you burn. A 300–500 calorie daily deficit is sustainable and effective. Use our calorie calculator to find your target
- Strength training: Building muscle increases your resting metabolic rate and improves body composition even without significant weight loss. Find your baseline burn with our BMR calculator
- High-protein diet: Protein preserves lean muscle during a calorie deficit and increases satiety. Aim for 1.6–2.2g of protein per kg of bodyweight when cutting
- Cardiovascular exercise: Creates additional calorie deficit and improves cardiovascular health markers alongside body composition
- Sleep and stress management: Poor sleep and chronic stress elevate cortisol, which promotes fat storage — particularly visceral (abdominal) fat
What Body Fat Percentage Should You Aim For?
The right target depends on your goals:
- General health: Men 15–20%, Women 22–28% — comfortable, maintainable, low health risk
- Athletic performance: Men 8–15%, Women 15–22% — optimal for most sports and fitness activities
- Competition physique (bodybuilding): Men 4–8%, Women 10–15% — not sustainable long-term; should only be attempted under qualified guidance
Body Fat Calculator FAQ
How accurate is this body fat calculator?
The US Navy method used here has an accuracy of approximately ±3–4% compared to DEXA scan results in most adults. It is less accurate for very muscular individuals (tends to overestimate fat) and very lean individuals (tends to underestimate fat). For the most accurate results, DEXA scanning, hydrostatic weighing, or Bod Pod testing are available at specialist sports science facilities.
How should I measure my waist for this calculator?
Measure your waist at the level of your navel (belly button), not at the narrowest point. Stand relaxed without holding your breath or sucking in. Take the measurement after breathing out normally. For consistency, always measure at the same time of day — morning before eating is ideal.
What is visceral fat and why does it matter?
Visceral fat is fat stored around your internal organs in the abdominal cavity. It is metabolically active and strongly linked to type 2 diabetes, cardiovascular disease, and metabolic syndrome — even in people with a “normal” total body fat percentage. A large waist circumference (over 94 cm for men, over 80 cm for women) is an indicator of elevated visceral fat regardless of overall body fat percentage.
How quickly can I reduce my body fat percentage?
A realistic and sustainable rate of fat loss is 0.5–1% body fat per month for most people. Losing more than this typically involves muscle loss alongside fat, which is counterproductive for body composition. At 0.5–1% per month, going from 28% to 22% body fat would take approximately 6–12 months — which is completely achievable with consistent effort.
Does age affect body fat percentage?
Yes — body fat percentage naturally increases with age as muscle mass declines (a process called sarcopenia). The acceptable body fat ranges in the table above apply broadly to adults under 60. Older adults generally maintain good health at slightly higher body fat percentages, as some fat storage becomes protective against illness and injury recovery.
Related Calculators
- BMI Calculator — Check your Body Mass Index alongside body fat percentage
- Ideal Weight Calculator — Find your healthy target weight using four medical formulas
- Calorie Calculator — Calculate your daily calorie target for fat loss
- BMR Calculator — Find your resting metabolic rate to plan your deficit
- Water Intake Calculator — Stay hydrated to support fat loss and performance