You can measure your body fat at home with a tape measure, a set of calipers, or a bathroom scale with bioelectrical impedance built in. For higher accuracy, clinical options like DEXA scans measure within 1%. The best method depends on your budget, how precise you need to be, and whether you care more about tracking trends over time or getting a single accurate snapshot.
The Tape Measure Method (Navy Formula)
The simplest approach uses a flexible tape measure and a formula developed by the U.S. Navy. For men, you measure two spots: the neck and the abdomen (at the navel). Subtract neck circumference from abdominal circumference to get your “circumference value,” then plug that number along with your height into the Navy’s body fat calculation chart or an online calculator.
For women, the formula requires three measurements: neck, natural waist, and hips. You add waist and hip circumferences, subtract the neck measurement, and use that circumference value with your height. The math behind it is logarithmic, so using an online Navy body fat calculator is the practical move. This method costs nothing, takes two minutes, and is accurate enough to track changes month to month. Pull the tape snug but not tight, measure on bare skin, and take each reading twice to confirm consistency.
Skinfold Calipers
Skinfold calipers pinch a fold of skin and underlying fat at specific body sites, then use the thickness of that fold to estimate total body fat. The most thorough version is the Jackson/Pollock 7-site method, which measures the chest, abdomen, thigh, tricep, subscapular (below the shoulder blade), suprailiac (just above the hip bone), and midaxillary (the side of the torso at armpit height).
A shorter 3-site version exists for quicker testing. For men it typically uses chest, abdomen, and thigh. For women it uses tricep, suprailiac, and thigh. You can buy a pair of calipers for $10 to $30, but technique matters a lot. Pinch too much skin or measure slightly off-site and your numbers shift. If you’re testing yourself, practice at each spot several times and average the readings. Having someone else do the pinching, ideally a trained fitness professional, improves reliability significantly. Calipers won’t give you a perfect number, but like the tape method, they’re excellent for spotting trends when you measure the same way each time.
Bioelectrical Impedance (Smart Scales)
Smart scales and handheld devices send a tiny electrical current through your body. Since lean tissue conducts electricity better than fat, the device estimates your body composition based on how much resistance it encounters. These scales are convenient and widely available for $30 to $150, but their readings swing based on factors that have nothing to do with actual fat loss or gain.
Body fat readings can vary 2 to 3% based on hydration alone. More water in your body means lower electrical resistance, which makes the scale report less fat. Dehydration does the opposite, inflating your reading. Exercise, a late meal, or even how much water you drank that evening can shift results. International guidelines recommend fasting 4 to 8 hours before a bioelectrical impedance test, though recent research suggests a light morning meal of roughly 200 calories doesn’t meaningfully affect the reading.
Compared to clinical methods, these scales carry a 5 to 10% margin of error on any single reading. That’s too wide to trust as an absolute number. Their real value is in tracking direction over weeks and months, but only if you control the conditions. Weigh yourself in the morning after using the bathroom and before eating or drinking. Same time, same routine, every time.
DEXA Scans
Dual-energy X-ray absorptiometry, commonly called a DEXA scan, is the gold standard for most people who want a precise body composition reading. You lie on a table for about 10 minutes while a low-dose X-ray scanner passes over your body, distinguishing bone, lean tissue, and fat. It also tells you where your fat is distributed, which matters for health in ways a single percentage can’t capture.
DEXA measures within 1% precision. A scan at a hospital imaging department runs $150 to $400, but wellness centers and mobile providers that bring machines to gyms or corporate offices charge less, typically $40 to $200 per scan. If you want one reliable baseline number and a clear picture of where you carry fat, a DEXA scan is worth the cost. Getting re-scanned every three to six months is a reasonable cadence for tracking progress.
Hydrostatic Weighing and the Bod Pod
Hydrostatic weighing, or underwater weighing, calculates body fat by comparing your weight on land to your weight fully submerged. Fat is less dense than water, so the difference reveals how much of your body is fat tissue. Accuracy sits around plus or minus 1.5%. The downside: you need to exhale all the air from your lungs while completely underwater, which some people find uncomfortable or difficult to do consistently.
The Bod Pod uses the same density principle but replaces water with air. You sit inside an egg-shaped chamber for a few minutes while it measures how much air your body displaces. It’s more comfortable than being dunked, with accuracy of plus or minus 1 to 3%. Both methods are typically found at university exercise science labs, sports medicine clinics, or specialized fitness facilities. A single session usually costs $25 to $75.
What Your Numbers Actually Mean
Body fat percentage varies significantly between men and women due to differences in essential fat (the minimum your body needs to function). According to the American Council on Exercise, the average nonathlete range is 25 to 31% for women and 18 to 24% for men. Dropping below 14% for women or 6% for men is considered dangerously low and carries its own health risks, including hormonal disruption and loss of bone density. The average body fat percentage in the United States is about 39.9% for women and 28.1% for men.
A single body fat percentage, though, doesn’t tell you everything. Where you carry your fat matters as much as how much you have. Visceral fat, the fat packed around your organs deep in the abdomen, drives far more health risk than the fat just under your skin. A normal visceral fat level is roughly 10% of your total body fat. You can get a rough sense of your visceral fat risk with just a tape measure: a waist circumference of 35 inches or more for women, or 40 inches or more for men (measured just above the hip bones), signals elevated risk for metabolic problems linked to visceral fat.
Getting Consistent Results
Whichever method you choose, the biggest mistake is comparing numbers across different methods. A DEXA scan and a bathroom scale will almost never agree, and that doesn’t mean either is broken. Pick one method and stick with it. Your goal is to track change over time using the same tool under the same conditions.
For any method, measure in the morning before eating, after using the bathroom, and in minimal clothing. Avoid testing right after a workout, when sweat loss and fluid shifts distort readings. If you’re using calipers or tape, have the same person take the measurements each session if possible. For bioelectrical impedance scales, keep your hydration routine as similar as you can from day to day, since even a few extra glasses of water the night before will show up in the reading. Taking three readings and averaging them, or measuring weekly and looking at the monthly trend rather than any single data point, smooths out the noise and gives you a much clearer picture of real progress.