What is body fat percentage?
Your body fat percentage is the share of your weight that comes from fat, as opposed to muscle, bone, water, and organs. Two people can weigh the same and look very different, because one carries more muscle and the other more fat. That is why this number tells you more about your shape and health than the scale alone.
Some fat is essential. Your body needs it for hormones, temperature, and protecting your organs. The goal is a healthy range for your sex, not the lowest number you can reach.
How it’s calculated
This calculator uses the US Navy circumference method. You measure a few body parts with a tape, and the formula reads those measurements to estimate fat. It uses base-10 logarithms, so the math is below for the curious:
- Men: 495 / (1.0324 minus 0.19077 times log10(waist minus neck) plus 0.15456 times log10(height)) minus 450
- Women: 495 / (1.29579 minus 0.35004 times log10(waist plus hip minus neck) plus 0.22100 times log10(height)) minus 450
Measure with a flexible tape, snug but not tight. Take the neck below the larynx, the waist at the navel, and (for women) the hip at the widest point. Once you have a percentage, you can read it against the standard fitness bands:
| Category | Men | Women |
|---|---|---|
| Essential fat | 2 to 5% | 10 to 13% |
| Athlete | 6 to 13% | 14 to 20% |
| Fitness | 14 to 17% | 21 to 24% |
| Average | 18 to 24% | 25 to 31% |
| Above average | 25%+ | 32%+ |
Bands shown are from the American Council on Exercise.
Frequently asked questions
What is a healthy body fat percentage?
It depends on your sex and your goals. For men, the fitness range sits around 14 to 17 percent and the average range runs 18 to 24 percent. For women, fitness is roughly 21 to 24 percent and average is 25 to 31 percent. Women carry more essential fat than men, so their healthy numbers are higher. These bands come from the American Council on Exercise.
How does the US Navy body fat method work?
You measure your height, neck, and waist (women also measure the hip), then the formula compares those circumferences. For men it uses waist minus neck against height. For women it uses waist plus hip minus neck against height. The result is a body fat percentage. It works because fat tends to settle around the waist and hip, so those measurements track total body fat reasonably well.
Is the body fat percentage calculator accurate?
It is a rough estimate, not a precise reading. The US Navy method usually lands within three to four percentage points of a DEXA scan for most people, but a stray tape measurement or an unusual build can throw it off. Use it to track change over time rather than as an exact figure, and talk to your clinician before making large changes.
Plans and guides
A lower body fat number comes from the same place as weight loss: a steady calorie deficit and enough protein to hold onto muscle. These plans and guides help with both.
Keep going: check your BMI, find your daily calories with the TDEE calculator, or build a routine from the exercise library.