FOODMANAC · KNOW YOUR NUMBERS
Body Fat Calculator
Estimate body-fat percentage from height and circumference measurements using the historical US Navy tape equations.
Your details
YOUR ESTIMATE
Start with your details
Enter your measurements to see the calculation and its assumptions.
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Search Foodmanac’s existing food database. Choose the correct preparation and compare its recorded nutrient basis with a portion you actually eat.
How to use this body fat calculator
Use a flexible, non-stretch tape without compressing skin. Measure the neck just below the larynx. For the male equation measure the abdomen at the navel; for the female equation measure the natural waist and widest hip circumference. Keep the tape level and remeasure. This is an approximation and not a military certification.
Formula and assumptions
All dimensions in inches. Male: 86.010 × log10(abdomen − neck) − 70.041 × log10(height) + 36.76. Female: 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387.
Example calculation
A male at 70 inches tall, with a 15-inch neck and 34-inch abdomen, has an estimate of approximately 17.5%.
Frequently asked questions
Is this as precise as a laboratory assessment?
No. Measurement technique and the population used to develop an equation affect accuracy.
Why does a small tape change alter the result?
The equation uses circumference differences; small measurement errors can materially affect the estimate.
Where exactly should I place the tape?
Neck: just below the larynx. Male abdomen: at the navel. Female waist: natural waist; hip: widest part of hips/buttocks. Keep the tape level without compressing skin.
Do I need a hip measurement for the male equation?
No. The hip field is hidden when the male equation is selected.
Is a small change in the result proof of fat loss?
No. Tape placement and tension can change the estimate. Repeat using the same technique.
What if I do not know which number to enter?
Read the explanation below each field. The initial values are examples, not your measurements. Use your scale or tape for body measurements. For a calorie budget, start with the Calorie or TDEE calculator. Optional water allowances can stay at zero.
Can I switch between kilograms and pounds or centimetres and inches?
Yes, where body measurements are used. Changing the unit selector converts the entered values. Imperial height is total inches: 5 feet 9 inches is 69 inches, not 5.9.
Who is this calculator intended for?
Generally healthy adults aged 20–78 who are not pregnant or breastfeeding. It is not intended for children, eating-disorder recovery, medically prescribed diets or fluid restrictions.
Why can another calculator give a different result?
Tools may use different equations, activity assumptions, unit conversions or rounding. Compare the method and inputs before comparing the result. None of these estimates is an exact measurement.
How do I save my result?
Calculate first, then choose Download PNG or Print / Save PDF. The export includes the inputs, results, explanation, method and references. Your site logo is included when configured; otherwise a Foodmanac wordmark is used.
Are my measurements sent to Foodmanac?
This plugin calculates in your browser and does not send your measurements. Food search sends the food name to the website. Other site plugins may have their own analytics or privacy behavior.
Sources and methodology
Source-backed equations are distinguished from Foodmanac planning presets. No result is an exact measurement or a medical prescription. Content version: 1.1.0.
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Measurements stay in this browser through this plugin. PNG and PDF exports contain the details you entered; share them only as you intend. Other site analytics and plugins have their own privacy behavior.