The circumference method was developed by Hodgdon and Beckett at the Naval Health Research Center in 1984 and is used in the Navy Physical Readiness Program. It is also popular with civilians because it needs only a tape measure.
How to use the Navy Body Fat Calculator
- Sex
- Age
- Height
- Neck circumference
- Waist circumference
- Hip circumference (women)
Results update as you type, and every field accepts the units shown in its menu.
How it works
Measure height barefoot, neck below the larynx, and waist at the navel (men) or the narrowest point (women); women also measure the hips. The calculator applies the metric Navy equations and compares the result with the Navy standards.
Navy body fat standards
| Age | Men | Women |
|---|---|---|
| 18–21 | 22% | 33% |
| 22–29 | 23% | 34% |
| 30–39 | 24% | 35% |
| 40 and over | 26% | 36% |
Tips
- Practise each event with the official standards and equipment before test day.
- Have a trained person take tape measurements – technique matters more than the tape.
- Check the current regulation; standards and score charts are updated regularly.
- Pace your run: an even pace beats a fast start and a slow finish.
Common mistakes to avoid
- Using an out-of-date score chart.
- Measuring the waist at the wrong landmark for your sex.
- Rounding measurements the wrong way – most regulations round down to the nearest half inch.
Inputs explained
| Field | What to enter |
|---|---|
| Sex | Choose one: Male, Female |
| Age | In years |
| Height | Units: cm, in, m, ft, mm |
| Neck circumference | Units: cm, in, m, ft, mm |
| Waist circumference | Units: cm, in, m, ft, mm |
| Hip circumference (women) | Units: cm, in, m, ft, mm |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Men: %BF = 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450
Women: %BF = 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450 (cm)
Worked example
Inputs — Sex: Male; Age: 25 years; Height: 178 cm; Neck circumference: 38.6 cm; Waist circumference: 90 cm; Hip circumference (women): 100 cm.
Results — Body fat = 19.7 %; Navy maximum for your age = 23 %; Result = Within the standard; Category (ACE) = Average.
Key terms
- PRP
- Navy Physical Readiness Program.
Frequently asked questions
What is the Navy body fat limit?
22–26% for men and 33–36% for women depending on age.
How accurate is the Navy method?
Usually within 3–4 percentage points of lab methods.
Do I need to be in the Navy to use it?
No – it works for any adult.