To measure your hips for a body fat estimate, wrap a flexible tape measure around the widest point of your buttocks while standing with your feet together. This single measurement, combined with your waist, neck, and height, feeds into formulas that estimate your body fat percentage without any specialized equipment. Getting the measurement right matters, though, because even a half-inch error can shift your result by a full percentage point or more.
Where Exactly to Measure
The correct spot is the maximum circumference of your buttocks, not your hip bones. Stand upright with your feet together and have someone wrap a soft, non-stretchy tape measure horizontally around the fullest part. The tape should be snug against your skin but not compressing the tissue. Keep it level all the way around, parallel to the floor. If you’re measuring yourself, do it in front of a mirror to check that the tape hasn’t dipped or risen in the back.
A few details that affect accuracy: measure against bare skin or thin underwear, not over jeans or thick fabric. Take three readings and use the average. Breathe normally and don’t flex your glutes. Record the number to the nearest half-centimeter or quarter-inch.
Why Hip Size Matters for Body Fat
Men and women store fat in fundamentally different patterns. Men tend to accumulate fat in the abdominal region (sometimes called android distribution), while women store more in the hips, buttocks, and thighs (gynoid distribution). Because of this difference, body fat formulas treat hip circumference differently depending on sex. For women, the hip measurement is a key input that helps the formula distinguish between lean mass and fat mass in the lower body. For men, most tape-measure formulas skip the hip entirely and rely on waist and neck measurements instead.
This difference in fat storage also has health implications. Lower-body fat is generally less metabolically harmful than abdominal fat, which is one reason premenopausal women tend to have lower cardiovascular and metabolic risk than men at similar overall body fat levels.
How the Calculation Works
The most widely used tape-measure formula is the U.S. Navy method. For women, it uses three measurements plus height: waist circumference, hip circumference, and neck circumference. The formula creates a “circumference value” by adding your waist and hip measurements, then subtracting your neck measurement. That value, along with your height, is plugged into a logarithmic equation that produces a body fat percentage.
For men, the formula only uses waist and neck circumference. Height is still part of the equation, but hips are left out because male fat distribution centers on the abdomen rather than the gluteal region.
You don’t need to do the math by hand. Dozens of free online calculators accept your measurements and return a result in seconds. Just make sure the calculator specifies it uses the Navy method (or whichever formula you prefer) and that you enter measurements in the correct units.
How to Take the Other Measurements
Since the hip measurement alone won’t give you a body fat number, you need the companion measurements done correctly too.
- Waist: Measure at the narrowest point of your torso, typically just above the navel. Keep the tape horizontal and don’t suck in your stomach. Take the reading at the end of a normal exhale.
- Neck: Measure just below the larynx (Adam’s apple), with the tape sloping slightly downward at the front. Don’t flare your neck or look up.
- Height: Stand against a wall without shoes. Use a flat object on top of your head to mark the wall, then measure from the floor to that mark.
How Accurate Is This Method
Tape-measure body fat estimates are useful for tracking trends over time, but they’re not precision instruments. Compared to DEXA scanning, which uses low-dose X-rays to map fat, lean tissue, and bone separately, anthropometric methods (tape and skinfold measurements) have a standard error of roughly 2.5 to 3 percentage points. That means if the formula says you’re at 25% body fat, your true value could reasonably be anywhere from about 22% to 28%.
This margin is similar to what you’d get from a consumer bioelectrical impedance scale, which showed a standard error around 3.1 percentage points in comparative research. The tape method’s main advantage is consistency: a tape measure doesn’t fluctuate with hydration, recent meals, or skin temperature the way electronic devices can. If you measure yourself the same way each time, you’ll get reliable trend data even if the absolute number is slightly off.
Waist-to-Hip Ratio as a Simpler Alternative
If you’re less interested in a specific body fat number and more interested in health risk, your waist-to-hip ratio (WHR) is a quick, well-validated metric. Divide your waist circumference by your hip circumference. For men, a ratio below 0.90 is considered normal. For women, the threshold is below 0.85. Values above those cutoffs indicate a higher proportion of abdominal fat and are associated with increased risk for cardiovascular disease, type 2 diabetes, and metabolic syndrome.
WHR has its own limitations. It can look “normal” in someone who carries excess fat evenly across the waist and hips, and it doesn’t distinguish between subcutaneous fat (just under the skin) and the deeper visceral fat that poses the most metabolic risk. Still, it takes about 30 seconds to calculate and gives you a meaningful snapshot of where your body stores fat relative to established health benchmarks.
Tips for Consistent Tracking
The real value of tape measurements comes from repeating them under the same conditions over weeks or months. Small changes in technique can create the illusion of progress or setback. A few habits that keep your data clean:
Measure at the same time of day, ideally in the morning before eating. Use the same tape measure each time, since cheap fabric tapes can stretch over months. Stand in the same spot and posture. Write down each raw measurement, not just the final body fat number, so you can spot which circumference is actually changing. And if someone else takes the measurement for you, try to use the same person each session, since different people apply slightly different tension to the tape.
Taking all three readings once every two to four weeks is frequent enough to catch real trends without obsessing over daily fluctuations from water retention, digestion, or normal biological variation.