- Select the measurement model.
- Enter height, neck, and waist circumference in centimeters.
- For the female model, also enter hip circumference.
- Review the estimated percentage and use repeated measurements to follow the trend.
Daily Body Fat Calculator
This calculator estimates daily body fat percentage from height and circumference measurements. It uses the U.S. Navy circumference method, a screening approach that can help track changes when measurements are taken consistently.
Use the result as a trend indicator rather than a diagnosis. Hydration, tape placement, posture, and body shape can shift the estimate, so comparisons are most useful when made under similar conditions.
Body measurements
cm
cm
cm
cm
Result
—
Estimated body fat
Fat mass at entered weight—
Lean mass at entered weight—
MethodU.S. Navy circumference
Male: 86.010 × log10(waist − neck) − 70.041 × log10(height) + 30.30
Female: 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 104.912
Measurements are converted to inches before the equations are applied.
What the result means
The main result is an estimated percentage of total body mass represented by fat.
Circumference equations can differ from laboratory methods and may be less accurate for some body shapes.
Given: Male model, height 175 cm, neck 38 cm, waist 88 cm.
Calculation: Convert to inches, then apply the male circumference equation.
Result: The calculator reports the estimated body fat percentage.
Why can my result change from one day to the next?
Tape position, abdominal tension, hydration, and measurement timing can change circumference readings.
Where should the waist be measured?
Use the same anatomical point each time and keep the tape level without compressing the skin.
Is this the same as BMI?
No. BMI uses only height and weight; this estimate uses body circumferences.
Can athletes use this method?
They can use it for trends, but muscular or atypical body shapes may reduce accuracy.
Should I act on one reading?
A series of consistent measurements is generally more informative than a single estimate.