📏 Body Fat Percentage Calculator

The Navy body fat method is approximately accurate within plus or minus 3-4% compared to DEXA scanning, the gold standard. It is more accurate than BMI for estimating body fatness and works well for average body types.

It may underestimate body fat in very muscular individuals since muscle mass increases circumferences in ways the formula does not account for. For very lean or very athletic individuals, a DEXA scan or bioelectrical impedance is more accurate.

Healthy body fat ranges differ by sex. For men, 10-20% is generally considered healthy, with 6-13% being athletic and 14-17% fit.

For women, 18-28% is generally healthy, with 14-20% being athletic and 21-24% fit. Essential body fat is approximately 2-5% in men and 10-13% in women; going below these levels can cause health problems.

BMI measures weight relative to height and says nothing about body composition. Two people with identical BMI scores can have very different body fat percentages depending on muscle mass.

A muscular athlete may show as overweight on BMI while having very low body fat. Body fat percentage directly measures what most people actually care about — how much fat their body is carrying — making it a more meaningful health metric for active people.

Measure your waist at the narrowest point, typically just above the belly button and below the rib cage. Stand relaxed with your stomach in a natural position — do not suck in or push out.

Keep the tape measure horizontal and snug but not tight enough to compress the skin. Measure first thing in the morning before eating for the most consistent results.

Most people can sustainably lose 0.5-1% body fat per month with a moderate calorie deficit and adequate protein. Faster rates are possible but typically come at the cost of losing muscle along with fat.

Combining a calorie deficit with resistance training preserves muscle, meaning the weight you lose is mostly fat rather than lean tissue. Track your progress monthly rather than weekly — body fat measurements have natural variation that obscures short-term trends.

Yes, this is called body recomposition: losing fat while gaining muscle at roughly the same rate, so total weight stays similar. It is most achievable for beginners, people returning from a long break, or anyone with significant fat to lose.

For experienced trainees, body recomposition is slower and harder than focused fat loss or muscle gain phases. Most experienced lifters cycle between cutting and building phases rather than trying to do both at once.

The Navy method for women uses height, neck, waist, and hip measurements (men do not need hip measurement). The added hip measurement accounts for women carrying a greater proportion of body fat in the hips and thighs.

Accuracy is similar to the men's formula — approximately plus or minus 3-4% versus DEXA — and works well for women with typical body shapes. Women with very pear-shaped or very straight body types may see slightly lower accuracy.

Body fat percentage is more meaningful than weight for tracking body composition changes, especially if you are exercising. Weight can stay flat while body fat drops (replacing fat with muscle), which weight tracking alone would miss.

Use both: weigh weekly for trend data, measure body fat monthly to track composition changes. The combination tells a more complete story than either metric alone.