Body Fat Percentage

About the Body Fat Percentage

Body fat percentage tells you something the scale cannot: how much of your weight is actually fat versus muscle, bone and water. It is a far better guide to fitness and health than weight alone, especially as you train.

This Body Fat calculator uses the U.S. Navy method, which estimates body fat from simple tape measurements. It is a practical, no-equipment screening estimate — not a lab measurement, but useful for tracking change over time.

How to use the Body Fat Percentage

1. Select your sex and enter your height.
2. Measure and enter your neck and waist (and hips for women).
3. Choose metric or imperial units.
4. Read your estimated body fat percentage and category.

Key features of the Body Fat Percentage

• Uses the U.S. Navy tape-measurement method
• No special equipment needed
• Shows body-fat category ranges
• Great for tracking change over time
• Private — calculated in your browser

How the Body Fat Percentage works

This calculator applies standard, peer-reviewed formulas used by health professionals and public-health bodies worldwide. Depending on the metric, that includes the World Health Organization (WHO) classification, NHS and CDC guidance, the Mifflin-St Jeor equation for metabolic rate, and the U.S. Navy method for body composition. Inputs are converted between metric and imperial units using exact factors so results are consistent whichever system you use.

All calculations are performed in your browser, so the health information you enter is never sent anywhere.

Tips & best practices

• Measure at the same time of day, in the same way, for consistent tracking — the trend matters more than any single number.
• Keep the tape snug but not compressing the skin, and measure the waist at the level the method specifies.
• This is an estimate; methods like DEXA are more precise, but consistency here still shows real progress.

Standards & accuracy

Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.

Important: these tools provide screening-grade estimates for general information and education only. They are not a medical diagnosis and do not replace professional advice. Always consult a qualified healthcare provider before making health decisions.

Who uses the Body Fat Percentage?

• Tracking fat loss while keeping muscle
• A better progress marker than the scale alone
• Setting realistic body-composition goals
• Fitness coaching and education

Privacy & security

The Body Fat Percentage runs entirely inside your web browser. Your data — whether that is a file, figures or text — is processed on your own device and is never uploaded to a server, stored or shared. There is no signup and no account, so you can use it as often as you like while keeping full control of your information. This makes it a safe choice even for confidential and sensitive work.

Why choose Toolinza?

• 100% free — no hidden charges, watermarks or usage caps.
• Private & secure — your data stays on your device.
• Standards-compliant — accurate results suitable for the UK, USA, Canada, Australia, EU, India, Pakistan, the Middle East and worldwide.
• Works everywhere — desktop, tablet and mobile.

Frequently asked questions