What is BFP (Body Fat Percentage)?

BFP stands for Body Fat Percentage - the proportion of your total body weight composed of fat tissue. It is a more accurate health indicator than weight or BMI alone.

How accurate is the Navy Method body fat calculator?

The U.S. Navy circumference method is a free, repeatable home estimate with typical variability of ±3-4%. It is most useful for tracking trends over time. BIA scales can vary significantly based on hydration. Neither method is equivalent to a DEXA scan or clinical assessment.

How do I calculate body fat percentage at home?

Use our free calculator with either the BMI-based formula (only needs height, weight, age, gender) or the U.S. Navy method (also requires neck, waist, and hip measurements with a tape measure).

What is a healthy body fat percentage?

For men, a healthy body fat percentage is typically 14-17% (fitness range). For women, a healthy range is 21-24%. Athletes tend to be lower: 6-13% for men, 14-20% for women.

How is BFP different from BMI?

BMI only considers height and weight, so it cannot distinguish between muscle and fat. BFP directly measures body composition. A muscular person may have a high BMI but a healthy BFP, while a skinny-fat person may have a normal BMI but a high BFP.

Body Fat Measurement Methods Comparison

Compare 6 body fat measurement methods side by side. Navy vs DEXA vs BIA vs skinfold. See accuracy, cost, time, and recommendations.

Which Method Should You Use?

Choose a method based on what equipment you have and your goal. If you have a tape measure, the Navy circumference method is the best home option for tracking trends. If you only know your height and weight, the BMI-based estimate gives a quick approximation. For clinical accuracy, a DEXA scan is the gold standard.

🥇

DEXA Scan

Grade: A

Dual-energy X-ray absorptiometry. The clinical gold standard. Uses low-dose X-rays to measure bone density, lean mass, and fat mass separately. Most accurate method available.

Accuracy

±1-2%

Cost

$100-250

Time

15-30 min

Pros: Highest accuracy (±1-2%), measures regional body fat distribution, also provides bone density data

Cons: Expensive ($100-250 per scan), requires clinic visit, not practical for frequent tracking

🥈

Hydrostatic Weighing

Grade: A-

Underwater weighing. Measures body density by comparing your weight on land vs. underwater. Fat is less dense than water and muscle/bone, so body density reveals fat percentage.

Accuracy

±2-3%

Cost

$50-100

Time

30-45 min

Pros: Very accurate (±2-3%), long-established method, used in research settings

Cons: Requires specialized facility, uncomfortable (full submersion), expensive for regular use

🥉

US Navy Method

Grade: B+

Uses a tape measure at neck, waist, and hips. Developed by the US Navy in the 1980s and validated on thousands of service members. Our calculator uses this method.

Accuracy

±3-4%

Cost

FREE

Time

2 min

Pros: Free, only needs a $3 tape measure, 2 minutes, not affected by hydration, results are very reproducible

Cons: Less accurate for very lean (<8%) or very muscular individuals, requires accurate measurement technique

📏

Skinfold Calipers

Grade: B

Pinches and measures the thickness of subcutaneous fat at specific body sites (3-7 sites depending on the formula). Estimates total body fat from these measurements.

Accuracy

±3-5%

Cost

$10-30

Time

10-15 min

Pros: Inexpensive ($10-30 one-time), good for tracking changes over time, not affected by hydration

Cons: Requires skill and practice — accuracy depends on technique, same person should measure each time, can be uncomfortable

⚠️

BIA Smart Scale

Grade: C-

Bioelectrical impedance analysis. Sends a tiny electrical current through your body. Fat resists current more than muscle, so impedance estimates body fat. Found in most smart scales.

Accuracy

±5-10%

Cost

$20-100

Time

30 sec

Pros: Convenient, fast (30 seconds), can measure daily, relatively cheap ($20-100 one-time)

Cons: Very unreliable — hydration status can swing readings ±10% daily. Drinking 500ml water = 2-3% error. Not useful for day-to-day tracking. Only useful for long-term trend (months).

📐

BMI Formula

Grade: D

Body Mass Index uses only height and weight. Estimates body fat through the Deurenberg formula (BMI + age + gender = estimated BFP). The least accurate but simplest method.

Accuracy

±8-15%

Cost

FREE

Time

10 sec

Pros: Free, instant, no measurements needed beyond height and weight

Cons: Cannot distinguish between muscle and fat — classifies muscular athletes as obese and skinny-fat individuals as healthy. Use only as a rough starting point.

Calculate Your Body Fat Now (Navy Method) →