Quick answer
What is a healthy body fat percentage?
For adults under 40, roughly 8 to 20% for men and 21 to 33% for women is considered healthy, with the ranges rising a few points with age (Gallagher et al.). Women naturally carry more essential fat. Body fat percentage is the share of your weight that is fat, and it says more about health than BMI because it separates fat from muscle. This calculator estimates it from tape measurements with the US Navy method, which is typically within 3 to 4 percentage points of a DEXA scan.
On this page
How to use the body fat calculator
- Choose units and your sex, then enter your age, height and weight.
- Measure your neck just below the Adam’s apple, with the tape sloping slightly down at the front.
- Measure your waist: at the navel for men, at the narrowest point for women. Relax, breathe out, don’t suck in.
- Women: measure your hips at the widest part of the buttocks.
- Press Calculate to see your body fat %, category, fat mass and lean mass. Measure again every 2 to 4 weeks, same time of day, and watch the trend.
Body fat percentage categories
The American Council on Exercise (ACE) groups body fat into five bands. The calculator uses these to label your result.
| Category | Women | Men |
|---|---|---|
| Essential fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32% and above | 25% and above |
Essential fat is the minimum needed for hormones, nerves and organs. Going below it is dangerous, and women need more of it than men for reproductive health.
Healthy body fat by age
Body fat tends to rise with age even at a stable weight, as muscle is gradually lost. These healthy ranges correspond to a BMI of 18.5 to 25:
| Age | Women | Men |
|---|---|---|
| 20–39 | 21–33% | 8–20% |
| 40–59 | 23–34% | 11–22% |
| 60–79 | 24–36% | 13–25% |
How the US Navy method works
The US Navy developed this method in the 1980s as a quick, equipment-free way to estimate body fat. It uses the fact that neck, waist and hip circumferences, relative to height, track body fat closely. The published equations use inches:
Women: %BF = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387
Metric measurements are converted to inches before the calculation. Fat mass is your weight × body fat %, and lean mass is what is left.
Measuring for an accurate result
- Measure in the morning, before eating, on bare skin.
- Keep the tape level and snug, but not pressing into the skin.
- Stand relaxed and breathe out normally before reading the waist.
- Take each measurement twice and use the average.
Ways to measure body fat compared
| Method | Typical accuracy | Notes |
|---|---|---|
| DEXA scan | ±1–2% | The clinical reference; also shows bone density and fat distribution |
| Hydrostatic weighing | ±1–2% | Accurate but needs a specialist lab |
| Skinfold calipers | ±3–4% | Good in trained hands; varies between testers |
| US Navy tape method | ±3–4% | Free, repeatable, great for tracking trends at home |
| Smart scales (BIA) | ±4–8% | Swings with hydration, meals and exercise |
Why body fat beats the bathroom scale
Scale weight lumps together muscle, fat, water and bone, so it can stall or even rise while you are getting leaner. Body fat percentage separates fat from everything else. Two people with the same height and weight, and the same BMI, can look completely different depending on how much of that weight is muscle.
Visceral vs. subcutaneous fat
Visceral fat sits deep around the liver, pancreas and intestines and is strongly linked to insulin resistance, type 2 diabetes and heart disease. Subcutaneous fat is the pinchable fat under the skin and is far less harmful. A large waist relative to your height, a ratio above 0.5, is the simplest warning sign of excess visceral fat.
How to lower your body fat
- Eat in a moderate calorie deficit. About 300 to 500 calories below maintenance. The calorie calculator gives you the number.
- Lift weights two to four times a week. Strength training tells your body to keep muscle, so the weight you lose is mostly fat.
- Eat enough protein. 1.6 to 2.2 g per kg of body weight protects muscle and keeps hunger down. See the protein calculator.
- Sleep 7 to 9 hours. Short sleep increases hunger and, in studies, shifts weight loss away from fat and toward muscle.
- Measure every 2 to 4 weeks. Body fat changes slowly; weekly readings mostly show noise.
Frequently asked questions
How accurate is the US Navy body fat calculator?
For most people it lands within about 3 to 4 percentage points of a DEXA scan, which is similar to skinfold calipers and better than most bathroom scales. Accuracy drops at the extremes (very lean or very high body fat) and if measurements are sloppy, so measure twice and use the average.
What is a healthy body fat percentage for men and women?
By the American Council on Exercise categories, men are “fitness” at 14 to 17% and “average” at 18 to 24%; women are “fitness” at 21 to 24% and “average” at 25 to 31%. Obesity starts at about 25% for men and 32% for women.
Why does the formula need hip measurements for women?
Women tend to store more fat around the hips and thighs, while men store more around the abdomen. Adding the hip measurement lets the women’s equation account for that pattern.
Can I lose fat from one specific area?
No. Spot reduction does not work: in a calorie deficit your body draws on fat from everywhere, in an order largely set by genetics. Stubborn areas are usually the last to go. A steady deficit, enough protein and strength training are what change the whole picture.
What is the most accurate way to measure body fat?
DEXA scans and hydrostatic (underwater) weighing are the most accurate widely available methods, usually within 1 to 2 percentage points. For tracking change at home, consistent tape measurements are more useful than a smart scale, whose readings shift with hydration.
How fast can I lower my body fat percentage?
At a sustainable rate of fat loss (about 0.5 to 1% of body weight a week), most people drop around 1 percentage point of body fat a month. Beginners who strength train can lose fat and gain muscle at the same time, which moves the percentage faster than the scale suggests.
What is lean body mass?
Everything that isn’t fat: muscle, bone, organs and water. It is your weight minus your fat mass. Lean mass drives your resting metabolism, which is why the BMR calculator can use it through the Katch-McArdle equation.
Sources
- Gallagher D, et al. Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. Am J Clin Nutr, 2000.
- American Council on Exercise. Percent body fat calculator and norms.
- Jackson AS, Pollock ML. Generalized equations for predicting body density of men. Br J Nutr, 1978.
- Ashwell M, et al. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors. Obes Rev, 2012.
This calculator gives estimates for healthy adults and is for information only. It is not a diagnosis or a substitute for advice from a doctor or registered dietitian.