Body Fat Calculator
Estimate your body fat percentage with the US Navy tape method, using a few simple measurements. Works in metric or imperial and runs in your browser.
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For general information and fitness planning only — not medical advice. Talk to a doctor or dietitian before making health decisions.
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Estimate Your Body Fat Percentage
This free body fat calculator uses the US Navy tape method, a widely used way to estimate body fat from a few tape-measure readings, no calipers or scales needed. Enter your height, neck and waist (plus hip for women), and it estimates your body fat percentage and a fitness category.
It works in metric or imperial and runs entirely in your browser. Body fat percentage is often more useful than weight alone, because it separates fat from muscle, but remember every method is an estimate.
How to Use the Body Fat Calculator
- 1Choose metric or imperial and your sex.
- 2Measure your height, neck and waist with a tape (women also measure the hip).
- 3Enter the measurements.
- 4Read your estimated body fat percentage and category.
Why Use MakeToolz's Body Fat Calculator?
US Navy method
The proven tape-measure formula used by the US Navy, no special equipment needed.
Fitness category
Shows where your result falls, from essential fat to above average.
Metric or imperial
Enter measurements in centimeters or inches.
Men and women
Uses the correct formula and measurements for each.
100% in your browser
No signup and nothing uploaded; it all runs locally.
Free and instant
Results update as you type your measurements.
Why Body Fat Percentage Matters
The scale only tells you total weight, not what that weight is made of. Two people at the same weight can look and perform very differently depending on how much is muscle versus fat. Body fat percentage captures that difference, which is why it is a popular metric for fitness goals. The US Navy method estimates it from the circumference of your neck, waist and (for women) hips relative to your height, using a formula validated against more expensive lab methods.
Because this runs entirely in your browser, your measurements stay private, and there is no signup or limit. Measure consistently, at the same time of day, for the most reliable tracking over time.
Typical Body Fat Ranges
- Essential fat: around 2 to 5% (men), 10 to 13% (women).
- Athletes: roughly 6 to 13% (men), 14 to 20% (women).
- Fitness: about 14 to 17% (men), 21 to 24% (women).
- Average: around 18 to 24% (men), 25 to 31% (women).
Measurement Tips
| Measurement | Where | Tip |
|---|---|---|
| Neck | Below the larynx | Tape sloping slightly down at front |
| Waist | At the navel | Relax, do not suck in |
| Hip (women) | Widest point | Feet together |
People Also Ask
How do I calculate body fat without calipers?
Use the US Navy tape method above. It only needs a measuring tape for your neck, waist and (for women) hips, plus your height.
Is body fat percentage better than BMI?
For many people it is more informative, because BMI cannot tell muscle from fat. A muscular person can have a high BMI but low body fat.
What body fat percentage shows abs?
Visible abs usually appear around 10 to 12% for men and 16 to 19% for women, though it varies with genetics and muscle size.
Why did my body fat reading change a lot?
Small measurement differences can shift the result. Measure the same way, same spot, same time of day, and track the trend rather than a single reading.
Is the body fat calculator free?
Yes, completely free with no signup and no limits. Everything runs in your browser.
Does it save my measurements?
No. Everything is calculated locally in your browser and nothing is uploaded or stored.