PastThePlateau
Free Tool

Body Fat Percentage Calculator

The scale measures total weight — not what that weight is made of. This calculator uses the U.S. Navy circumference method to estimate your body fat percentage with just a tape measure, so you can see whether your body composition is still changing during a plateau.

Educational estimate only. Circumference-based methods are useful for tracking trends over time but are less precise than clinical methods like DEXA.

Calculate your body fat %

Measure just below the larynx.
Measure at the navel (men) or narrowest point (women).
Measure at the widest point.

This tool uses the published U.S. Navy circumference formula and the commonly used ACE body-fat category ranges. Measurement technique affects accuracy — measure at the same time of day, without clothing over the tape, for the most consistent trend over time.

Why body fat % can matter more than the scale

A stalled scale is the single most common reason people think a GLP-1 medication has "stopped working." But weight and fat loss aren't the same thing. If you've added resistance training or increased your protein intake, it's possible to lose fat and hold onto (or even slightly gain) muscle at the same time — a pattern often called body recomposition. On the scale, that can look like a plateau even though your body is still changing.

Tracking body fat percentage every few weeks — alongside the Plateau Checker and how your clothes fit — gives you a fuller picture than the scale number alone.

Are you eating enough protein?

Protein intake is one of the biggest levers for preserving muscle while losing fat.

Try the protein calculator →

Is this really a plateau?

Run the numbers on your recent weigh-ins to see if you're in a genuine stall.

Use the Plateau Checker →