UltimateTools
Health & Wellness

How to Use the Body Fat Calculator

Enter your height along with neck and waist measurements (and hip measurement, for women) — the calculator applies the Navy body fat formula to estimate your body fat percentage, along with which general category it falls into.

The Body Fat Calculator uses the standard Navy tape-measurement method — here's how to take accurate measurements before entering them.

Taking accurate measurements

Measure directly against skin (not over clothing) with the tape snug but not compressing the tissue, at a consistent, standard location for each measurement — inconsistent technique is the single biggest source of an inaccurate result with this method.

Reading and tracking the result

The result is a percentage estimate, along with a general category — treat it as a starting reference point and track the trend over time with consistent measurement technique, rather than focusing heavily on the precision of any single reading.

Frequently asked questions

How often should I remeasure?

Monthly is a reasonable cadence for tracking a meaningful trend — body composition changes gradually, so more frequent measurement mainly adds noise from minor day-to-day measurement variation rather than revealing genuine change.

Is this calculator accurate enough for athletic performance tracking?

It provides a reasonable general estimate, but for precise athletic or clinical purposes, a more accurate method like DEXA scanning is preferable — this tool is best used as an accessible, ongoing trend-tracking estimate.