Body Fat Calculator
Body Fat Calculator
All you need is a tape measure. Get a quick estimate of your body fat percentage with the US Navy method.
Heads up: tape measurements can be off by a few points. Don't treat the number as gospel. Use it to track your own trend, measured the same way each time.
Want a number you don't have to measure by hand?
The ScanFit Body Scanner reads your fat and your muscle for you, so you can put the tape measure away.
See The Body Scanner Check My BMIBody fat percentage is the share of your weight that is fat. For men, roughly 14 to 24% covers fitness to average. For women, roughly 21 to 31%. The US Navy method estimates it from your height, neck and waist, plus your hips if you're a woman.
Why Body Fat Matters More Than Your Weight
Two people can weigh exactly the same and look completely different. The scale can't tell fat from muscle, bone or water. Body fat percentage can.
That's why it's the number to watch when you're losing fat, building muscle, or wondering if a plateau is real. Where the fat sits matters too. Extra fat around your waist is linked to more health risk than fat elsewhere, which is why your waist is part of the formula.
How The Navy Method Works
The US Navy came up with this one so it could estimate body fat without any special equipment. You measure your neck and waist (plus your hips if you're a woman), add your height, and a formula turns it into a body fat percentage. Men and women get different formulas because they carry fat differently.
So how good is it? Studies comparing it with lab methods like DEXA find it reasonable across groups of people. For one person, though, it can be off by several points, especially if you're very lean, very muscular or very heavy.
How To Measure Without Fooling Yourself
- Stand relaxed, in bare skin or thin clothes. Keep the tape level and snug, not squeezing.
- Waist: at the navel for men, at the narrowest point for women.
- Measure twice and use the average.
- Do it at the same time of day, ideally in the morning, so your numbers are comparable.
Body Fat Percentage Ranges
| Category | Women | Men |
|---|---|---|
| Essential fat | 10 to 13% | 2 to 5% |
| Athletes | 14 to 20% | 6 to 13% |
| Fitness | 21 to 24% | 14 to 17% |
| Average | 25 to 31% | 18 to 24% |
| Obese | 32%+ | 25%+ |
Ranges from the American Council on Exercise. Healthy ranges also shift a bit with age.
How To Lower Your Body Fat Percentage
- Eat a modest calorie deficit. Around 20% below what you burn is enough. Crash diets cost you muscle. Use the calorie calculator to find your number.
- Hold on to your muscle. Lift weights two or three times a week and eat plenty of protein, so the weight you lose is fat.
- Move every day. Walking adds up and is easy to keep doing.
- Be patient. A realistic pace is about half a percentage point to one point a month. Measure the same way, at the same time, to see the real trend.
Track It Without The Tape Measure
A tape measure is fine for a one-off estimate. Doing it every week gets old fast. The ScanFit Body Scanner does the tracking for you. Step on barefoot, hold the handle, and it reads your body from your hands to your feet, then splits it into:
- Body fat percentage
- Muscle mass
- Visceral fat
- Body water
Everything lands in the free ScanFit app, so you can watch your trend week by week instead of guessing from one weigh-in. Up to 10 people can share one scanner, it syncs with Apple Health, Garmin and Health Connect, and you get 100 days to try it. Don't love it? Send it back.
“I had another scale that was not quite as accurate. This one’s much better.”Robert Maxvill, United States · Read on Trustpilot
See The Body Scanner Scanner + Food Scale Bundle
Not for anyone with a pacemaker or another implanted electronic device. If you're pregnant, check with your doctor first.
Frequently Asked Questions
What is a healthy body fat percentage?
For men, roughly 14 to 24% covers fitness to average. For women, roughly 21 to 31%. Essential fat, the minimum you need to stay healthy, is about 2 to 5% for men and 10 to 13% for women. Healthy ranges creep up a little with age.
How can I lower my body fat percentage?
Eat a modest calorie deficit, lift weights to keep your muscle, get enough protein and walk daily. Expect roughly half a point to one point a month, and measure the same way each time.
How accurate is the Navy body fat calculator?
It's a solid estimate, but for any one person it can be off by several percentage points. It works best for tracking your own changes over time, measured the same way each time.
How do I measure body fat at home?
The tape-measure method on this page is the cheapest. Measure your neck and waist (and hips for women), enter your height and let the formula do the rest. A body composition scale reads it for you in seconds.
What's the difference between body fat and BMI?
BMI only uses height and weight, so it can't tell fat from muscle. Body fat percentage shows how much of your weight is actually fat, which is the number to watch when you're training or changing how you eat.
How often should I measure my body fat?
Once a week or every two weeks, under the same conditions, ideally in the morning. Day-to-day changes are mostly water, so the trend over several weeks is what counts.
Does the Navy method work if I'm muscular?
Less well. It reads your waist and neck, so a very muscular build can throw the estimate off by a few points. Track your own trend instead of trusting a single reading.
How do I get a more precise number?
A DEXA scan is the usual reference, but that means a clinic visit. A body composition scanner at home lets you check in as often as you like.
This calculator is for general information only and isn't medical advice. For questions about your health, weight or nutrition, talk to your doctor or a registered dietitian.