Body Fat Calculator
Range: 15 - 80
Range: 80 - 400
Range: 1 - 8
Range: 0 - 11
Body Measurements
At navel level
Below larynx
Body Fat Percentage
17.5%
Fitness
Body Composition
144.4 / 30.6
Lean / Fat mass (lbs)
Fat Mass
30.6 lbs
17.5% of total weight
Lean Mass
144.4 lbs
82.5% of total weight
Body Fat Categories (Men)
| Category | Range |
|---|---|
| Essential Fat | 2-5% |
| Athletic | 6-13% |
| Fitness | 14-17% |
| Average | 18-24% |
| Obese | 25%+ |
How to Measure
- Waist: Measure at the narrowest point, or at navel level for men. Keep the tape level.
- Neck:Measure just below the larynx (Adam's apple) with tape sloping slightly downward.
- Take measurements in the morning before eating. Keep tape snug but not compressing skin.
About This Method
The US Navy method uses body circumference measurements to estimate body fat percentage. While convenient, it's less accurate than methods like DEXA scans or hydrostatic weighing. Results can vary by ±3-4%. This method works best for people with average body compositions.
Calculator Assumptions
- Formula: US Navy circumference method (Hodgdon-Beckett equations)
- Accuracy: ±3-4% compared to DEXA; less accurate for very lean or obese individuals
- Measurement timing: Results vary with hydration, time of day, and recent meals
- Categories: Based on American Council on Exercise guidelines; optimal ranges vary by age
- Limitations: Does not account for muscle mass distribution, bone structure, or ethnicity
About the Body Fat Calculator
The Body Fat Calculator estimates the percentage of your total body weight that is fat tissue, as opposed to lean mass like muscle, bone, and organs. It commonly uses the U.S. Navy circumference method, which derives an estimate from measurements such as height, neck, waist, and (for women) hip circumference. This approach is popular because it requires only a tape measure rather than calipers, hydrostatic weighing, or a DEXA scan.
The Navy formula works through logarithmic regression equations that relate body circumferences to measured body fat. For men it uses waist and neck against height; for women it adds hip circumference, since fat distribution differs by sex. The result is an approximation, so accuracy depends heavily on taking measurements at the correct anatomical landmarks and pulling the tape snug but not compressing the skin.
Body fat percentage is more informative than weight alone for fitness goals, because two people of identical weight can have very different compositions. Typical reference ranges put essential fat around 2 to 5 percent for men and 10 to 13 percent for women, with athletic, fitness, and average bands rising from there. The calculator pairs naturally with the Ideal Weight Calculator and BMI Calculator to round out a body-composition assessment.
For the most consistent tracking, measure at the same time of day under similar conditions and average two or three readings per site. Because circumference methods can drift by several percentage points versus lab methods, focus on the trend over weeks rather than any single figure. Combine it with the TDEE Calculator and Macros Calculator if your goal is to lose fat while preserving muscle.
Frequently asked questions
- How accurate is the Navy body fat method?
- It is generally within about three to four percentage points of lab methods like DEXA when measurements are taken correctly. It is far more accurate for tracking change over time than for a single absolute reading.
- Where exactly should I measure my waist?
- For the Navy method, men measure at the navel and women at the narrowest point of the waist. Keep the tape horizontal and snug without compressing the skin, and measure after a normal exhale.
- Why does the women's formula need a hip measurement?
- Women typically store more fat around the hips and thighs, so adding hip circumference improves the regression model's accuracy for female body composition compared to using waist and neck alone.
- What is a healthy body fat percentage?
- Healthy ranges differ by sex and age, but roughly 14 to 24 percent for men and 21 to 31 percent for women are common 'fitness to average' bands. Essential fat sits much lower and going below it is not advisable.