Body Fat (US Navy) Formula Explained, With Examples
Every body fat (us navy) result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
US Navy circumference formula using log10 of waist, neck (and hip) and height.
What each input means
- Sex: choose from Male, Female.
- Height (cm): the value you enter in the calculator.
- Neck (cm): the value you enter in the calculator.
- Waist (cm): the value you enter in the calculator.
- Hip (cm, women only): the value you enter in the calculator.
Example
For example, with these inputs:
- Sex: Male
- Height (cm): 172
- Neck (cm): 38
- Waist (cm): 85
- Hip (cm, women only): 95
the calculator returns:
- Body fat: 17.45%
How the result changes
The table keeps the other inputs at their example values and changes height (cm).
| Height (cm) | Body fat |
|---|---|
| Male | 17.45% |
| 86 | 38.93% |
| 129 | 26.13% |
| 215 | 10.93% |
| 258 | 5.74% |
Why it matters
Health numbers are most useful when you track them consistently. A quick calculation turns everyday measurements into something you can act on, whether that is planning meals, training for a run or preparing for a clinic visit.
Research has shown that Asians tend to develop conditions such as type 2 diabetes and heart disease at lower body weights than Europeans. That is why the Health Promotion Board recommends lower BMI cut-offs for Singaporeans, with 23 marking the start of moderate risk.
Energy needs depend on age, sex, size and activity. Formulas such as Mifflin-St Jeor estimate resting needs, and an activity multiplier turns that into daily needs. Real requirements vary by a few hundred calories, so adjust based on how your weight changes over several weeks.
Singapore's tropical climate means you lose more fluid through sweat, even when you are not exercising. Thirst, urine colour and how you feel are good guides, and needs rise during outdoor activity or heat waves.
Related calculations
- Protein Intake Calculator: Estimates daily protein needs.
- Steps to Kilometres Calculator: Converts step counts (like your Healthy 365 tracker) to distance.
- Running Pace Calculator: Calculates pace for runs like the Standard Chartered Marathon or IPPT 2.4 km.
- Calories Burned Calculator: Estimates calories burned with MET values.
Use the Body Fat Calculator (US Navy) to plug in your own numbers.
Run your own numbers: Body Fat Calculator (US Navy)