How do I find body fat without a smart scale?

A tape measure is enough: the US Navy method estimates body fat from height and neck and waist measurements (women also hips). Accuracy is about ±3–4%, enough to track progress.

What body fat percentage is normal?

For men, fitness/average is roughly 14–24%, for women 21–31% (higher by physiology). Below the essential level (5% men / 13% women) is harmful, above 25/32% is obese by body composition.

Why is body fat higher in women?

It’s normal: the female body needs more fat for hormonal health and reproduction. That’s why the categories differ for men and women and can’t be compared directly.

What is waist-to-hip ratio?

It’s waist circumference divided by hip circumference. It shows where fat sits: on the belly (higher risk) or hips. Above 0.90 for men and 0.85 for women is elevated.

How accurate is the tape method?

The error is about ±3–4% versus reference methods (DEXA, underwater weighing). It’s fine for tracking progress; for medical precision you need instrumental measurement.

Body fat percentage

Enter your sex, height and neck and waist measurements (women also hips) — the calculator estimates body fat with the US Navy method and gives your category. Add weight to see fat mass and lean (muscle) mass, and with a hip measurement it also computes your waist-to-hip ratio.

Estimate body fat from measurements

Enter sex, height and measurements — the result appears instantly.

Body fat categories (ACE)

American Council on Exercise guidelines. Women’s healthy body fat is higher than men’s — that’s physiology.

Category	Men / Women
Essential fat	2–5% / 10–13%
Athletes	6–13% / 14–20%
Fitness	14–17% / 21–24%
Average	18–24% / 25–31%
Obese	≥ 25% / ≥ 32%

How body fat is measured from tape measurements

The US Navy method estimates body fat from body measurements and height: for men from the “waist − neck” difference, for women from “waist + hip − neck”. It’s a simple, equipment-free approach; accuracy is about ±3–4% versus reference methods.

Measure with a tape resting gently against the skin: neck below the Adam’s apple, waist at the navel, hips at the widest point. Measurement accuracy strongly affects the result.

Fat mass and lean mass

Add your weight and the calculator splits it into fat mass and lean mass (muscle, bone, water, organs). Lean mass matters for calorie and protein targets: deriving needs from it, not total weight, is more accurate for athletic and lean people.

Waist-to-hip ratio (WHR)

The ratio of waist to hip circumference shows your fat distribution. An abdominal (“apple”) pattern — fat around the belly — carries higher heart and metabolic risk than a hip (“pear”) pattern. WHR above 0.90 for men and 0.85 for women is considered elevated (WHO).

Frequently asked questions

A tape measure is enough: the US Navy method estimates body fat from height and neck and waist measurements (women also hips). Accuracy is about ±3–4%, enough to track progress.
For men, fitness/average is roughly 14–24%, for women 21–31% (higher by physiology). Below the essential level (5% men / 13% women) is harmful, above 25/32% is obese by body composition.
It’s normal: the female body needs more fat for hormonal health and reproduction. That’s why the categories differ for men and women and can’t be compared directly.
It’s waist circumference divided by hip circumference. It shows where fat sits: on the belly (higher risk) or hips. Above 0.90 for men and 0.85 for women is elevated.
The error is about ±3–4% versus reference methods (DEXA, underwater weighing). It’s fine for tracking progress; for medical precision you need instrumental measurement.

Match supplements to your body composition

Tell us your goal and attach your labs — AI matches supplements to your lean mass, deficiencies and aims.

Get my match

This calculator is for reference and information only and gives an estimate with an error of about ±3–4%. Accurate body composition needs instrumental methods.