The formula this calculator uses
Body Fat Calculator (U.S. Navy Method)
Men: 495 / (1.0324 − 0.19077×log10(waist−neck) + 0.15456×log10(height)) − 450
Women: 495 / (1.29579 − 0.35004×log10(waist+hip−neck) + 0.22100×log10(height)) − 450
Example: Male, 175 cm, neck 38 cm, waist 85 cm → ≈ 15–18% body fat
U.S. Navy body-fat method
This calculator implements the official U.S. Navy circumference formula. It requires only a tape measure and is widely used for fitness tracking and military standards. The method is based on the principle that body fat distribution affects circumference ratios — specifically, the relationship between neck, waist, and hip measurements relative to height.
Body Fat Calculator for Male
The body fat calculator for males uses the U.S. Navy formula: 495 / (1.0324 − 0.19077×log10(waist−neck) + 0.15456×log10(height)) − 450. It requires height, neck, and waist measurements in centimeters. Healthy body fat for men is typically 10–20%, with athletes often ranging between 6–13%.
Body Fat Calculator for Female
The body fat calculator for females uses the U.S. Navy formula: 495 / (1.29579 − 0.35004×log10(waist+hip−neck) + 0.22100×log10(height)) − 450. It requires height, neck, waist, and hip measurements in centimeters. Healthy body fat for women is typically 18–28%, with athletes often ranging between 14–20%.
How to Calculate Body Fat Percentage at Home
You don't need expensive equipment to estimate your body fat percentage at home. Here are three reliable methods:
- U.S. Navy Tape Method: Measure your neck, waist, and (for women) hips with a tape measure, then use this calculator. This is the most accessible method.
- Skinfold Calipers: Use a body fat caliper to measure skinfold thickness at 3–7 sites (abdomen, thigh, chest, triceps, etc.). Accuracy is ±3–5% with proper technique.
- Smart Scale (BIA): Bioelectrical impedance scales send a small current through your body to estimate fat. Convenient but less accurate (±5–8%).
Body Fat Percentage Chart
The following chart shows body fat percentage categories for men and women, based on guidelines from the American Council on Exercise (ACE):
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Measurement tips
Measure in the morning before eating, keep the tape snug but not compressing the skin, and take each measurement twice for consistency. For men, measure the waist at the navel level. For women, measure the waist at the narrowest point and the hips at the widest point. The neck should be measured just below the larynx (Adam's apple) with the tape sloping slightly downward at the front.
How to use this calculator
- Select your sex from the dropdown.
- Enter your height in centimeters.
- Enter your neck, waist, and (if female) hip measurements in centimeters.
- Your body fat percentage and category update instantly.
Related health calculators
Body fat percentage is just one metric. You might also find these tools useful:
- Check your weight category with our BMI Calculator.
- Calculate your daily calorie needs with our Calorie Calculator.
- Track your workout and rest intervals with our Time Calculator.
Frequently asked questions
Is 20% body fat skinny?
For men, 20% body fat falls into the 'average' category — not skinny, but not obese either. For women, 20% body fat is considered 'athletic' or 'fit' and is on the leaner side. Whether 20% looks skinny depends on your sex, muscle mass, and body composition.
How do you calculate body fat%?
Body fat percentage can be calculated using several methods: the U.S. Navy circumference formula (used in this calculator), skinfold calipers, bioelectrical impedance scales, DEXA scans, and hydrostatic weighing. The Navy method uses neck, waist, and hip measurements along with height to estimate body fat.
How do I check my body fat percentage?
You can check your body fat percentage at home using a tape measure and the U.S. Navy formula, a body fat caliper, or a smart scale with bioelectrical impedance. For clinical accuracy, visit a facility that offers DEXA scan, Bod Pod, or hydrostatic weighing.
How can I calculate my body fat percentage?
To calculate body fat at home, you need a measuring tape. Measure your neck, waist, and (for women) hips in centimeters. Then enter these values into this calculator. Alternatively, use a body fat caliper to measure skinfold thickness at specific sites, or use a bioelectrical impedance scale.
Is 30% body fat chubby?
For men, 30% body fat is classified as obese and would generally appear chubby or overweight. For women, 30% body fat falls into the 'average' to 'above average' range and may not necessarily look chubby, depending on height and frame.
Are abs visible at 20% body fat?
No. Visible abs typically require body fat levels of around 10–14% for men and 18–22% for women. At 20% body fat, most men will not have visible abs, though some may see faint outlines if they have well-developed abdominal muscles.
What is the most accurate body fat calculator?
The most accurate methods are clinical: DEXA scan (±1–2%), hydrostatic weighing (±2–3%), and Bod Pod (±2–3%). For at-home use, the U.S. Navy circumference method (±3–4%) and skinfold calipers (±3–5%) are the most reliable.
Does a body fat caliper work?
Yes, a body fat caliper is a reliable at-home tool when used correctly. It measures skinfold thickness at specific body sites (usually 3–7 points) and estimates body fat percentage. Accuracy is ±3–5% with proper technique.
How accurate is the Navy method?
It is a solid field estimate (±3–4%) when measurements are taken carefully, but DEXA or hydrostatic weighing remain the gold standards.
Where should I measure waist and neck?
Waist at the narrowest point (or navel level for men), neck just below the larynx, hips at the widest point.
Can I use inches instead of cm?
Convert inches to cm (×2.54) before entering values, or the result will be wrong.