Body Fat Percentage Calculator

It depends on sex and age. The Gallagher ranges, which link the NIH healthy BMI limits to body fat, run from 21 to 33 percent for women and 8 to 20 percent for men at ages 20 to 39, from 23 to 34 and 11 to 22 percent at 40 to 59, and from 24 to 36 and 13 to 25 percent at 60 to 79. The table under the result lists them all. They are provisional ranges, not a diagnosis.

It is a rough screening estimate, not a precise measurement. The equations were reported to have a standard error of 3 to 4 percentage points. Against a DXA scan in fit US Marines they underestimated men by about 2.5 points and overestimated women by 1 to 2, and individual results scattered by 4 to 5 points (Potter and colleagues, 2022). In Army recruits they underestimated by about 6 points (Foulis and colleagues, 2023). Use it to follow your own trend.

About once a month is plenty. Body fat moves slowly: for a 200-pound person at 30 percent, losing a pound of pure fat lowers it by only about 0.35 points (59 / 199 = 29.65 percent). The tape method repeats to about 1 point between trained observers, so more frequent readings mostly show noise. Measure at the same time of day with the same tape and posture, and track your waist and how clothes fit too, because tape formulas also missed real changes over 8 weeks in Army recruits.

Women usually store more fat on the hips and thighs than men, who tend to store it around the abdomen. So the women’s equation adds the hips to the waist (waist + hips − neck), while the men’s equation uses the abdomen alone (abdomen − neck). Researchers describe the pear-shaped fat distribution of many women and its different metabolic meaning from the central fat typical of men (Karastergiou and colleagues, 2012).

They use different methods. A smart scale sends a weak electrical current through your body (bioelectrical impedance) and infers fat from how easily it passes, while this calculator uses tape measurements and a formula. An NIH panel noted that impedance readings change with hydration, recent food and drink, exercise, body position and temperature. In one study of 85 medical students the Navy formula read slightly higher than impedance. Differences of a few points are normal, so compare readings only within one method.

Yes. Researchers call it normal weight obesity: a healthy BMI of 18.5 to 24.9 with a high body fat percentage. In a US national survey of 6,171 adults with a normal BMI, those in the top third for body fat (over 23.1 percent in men and 33.3 percent in women) had about four times the rate of metabolic syndrome (16.6 versus 4.8 percent), and women had a higher risk of cardiovascular death (Romero-Corral and colleagues, 2010).

It depends on your weight and pace, but the arithmetic is simple. At 180 pounds and 30 percent you carry 54 pounds of fat and 126 pounds of lean mass. Keeping the lean mass, 20 percent means weighing 157.5 pounds, so you lose 22.5 pounds of fat. NIDDK suggests an initial goal of 5 to 10 percent of your weight within 6 months, which is 9 to 18 pounds here, so expect roughly 8 to 15 months, and longer if you also lose muscle.

There is no official number, because it depends on where your body stores fat and how large your abdominal muscles are. Lean athletes show the lowest values: in a 1983 study of American Olympic athletes the sport averages ran from about 6 to 13 percent for men and 14 to 22 percent for women, and sprinters and marathoners sat near the bottom. Very low levels are hard to hold, so check with a doctor before aiming below the healthy range.

There is no rule, and it is partly personal. For a man aged 20 to 39, 25 percent is where the Gallagher table starts its very high class, and at 40 to 59 it is in the high class, so most would cut first. For a woman up to age 79, 25 percent is inside the healthy range, so either goal can make sense. Strength training with enough protein helps you keep or gain muscle; see the protein calculator. Ask a doctor or dietitian if you have a health condition.

On average yes, and the ranges reflect it. At the same BMI older adults carry more body fat, so Gallagher and colleagues set higher limits with age: the healthy range starts at 8 percent for men aged 20 to 39 and 13 percent at 60 to 79, and for women at 21 and 24 percent. Age is also an input of the BMI formula, which adds 0.23 points of body fat for every extra year (Deurenberg and colleagues, 1991).

Pick a method above. For the Navy tape method measure your neck and abdomen (men) or neck, waist and hips (women) in inches, add your height, and the equation does the rest. With no tape, choose the BMI formula, which needs only age, sex, height and weight. Both give estimates, and the BMI formula has a standard error of about 4 percentage points. For lab accuracy you need a DXA scan or a similar test.

Use a flexible tape held flat against bare skin, snug but not squeezing. Measure the neck just below the larynx. For men, measure the abdomen at the level of the navel. For women, measure the waist at the narrowest part of the torso and the hips at the widest part of the buttocks. Stand relaxed, breathe out normally, and take each measurement twice, using the average.

BMI compares weight with height and cannot tell fat from muscle, while body fat percentage is the share of your weight that is fat. Two people with the same BMI can have very different body fat. The BMI formula here turns BMI, age and sex into a body fat estimate, but a tape measurement shows more about where fat sits. Check your BMI with the BMI calculator.

The equations differ by sex, so choose the method for your sex. The men’s Navy equation uses neck, abdomen and height, the women’s uses neck, waist, hips and height, and the BMI formula takes 10.8 points off for men. The classes differ too, because women carry more body fat than men on average. This one calculator covers both.