Free Body Fat Percentage Calculator

Calculate your body fat % using 5 proven methods. Get lean mass, fat mass, and category breakdown. No signup, no uploads — 100% private.

1 Select Biological Sex
2 Measurement System
3 Measurement Method
BMI-based estimation using age and gender
4 Enter Your Measurements
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Select your gender, choose a method, enter measurements, and click calculate.

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Privacy First — No Server Uploads
Your measurements are processed entirely in your browser. They never leave your device. No uploads, no tracking, no signup.

Free Body Fat Percentage Calculator – 5 Methods, Instant Results

Look, I've been there. You want to track your fitness progress, but BMI just doesn't tell the whole story. You've got a tape measure or a set of calipers, but doing the math by hand is a pain. Or maybe you just want a quick estimate without signing up for some app that wants all your data. That's why I built this — a free body fat percentage calculator that actually works and keeps your data private.

This tool gives you 5 different calculation methods — Heritage BMI, US Navy, YMCA, and Jackson/Pollock 3-site, 4-site, and 7-site caliper formulas. Pick the one that fits your tools and get your body fat percentage, lean body mass, fat mass, and your fitness category — all in one place. No uploads, no watermarks, no begging you to upgrade to "Pro."

🧬 5 Measurement Methods

Heritage BMI, US Navy, YMCA, Jackson/Pollock 3/4/7-site — choose what fits your tools.

📐 Metric & Imperial

Switch between cm/kg and in/lbs. The calculator handles both seamlessly.

📊 4 Key Results

Get body fat %, category, lean mass, and fat mass — everything you need in one view.

🧑‍⚕️ Category Explanation

Each result includes a plain‑English explanation of what your category means.

🔒 100% Private

Your measurements never leave your browser. No uploads, no servers, no privacy concerns.

⚡ No Signup

Use it right now. No registration, no email, no credit card. Just calculate and go.

How to Calculate Your Body Fat Percentage for Free

  • Select your sex – Body fat distribution differs between males and females, affecting calculation accuracy.
  • Choose your units – Imperial (inches/pounds) or Metric (centimeters/kilograms).
  • Pick a method – BMI-based (quick estimate), Tape Measure (US Navy, YMCA, Covert Bailey), or Caliper (Jackson/Pollock).
  • Enter measurements – Height, age, weight, plus method‑specific measurements like waist, neck, hips, or skinfold sites.
  • Click "Calculate Body Fat" – Get your results instantly, with a category breakdown and explanation.

That's it. No hidden steps. No "sign up to see results" nonsense. Just calculate and go.

Which Method Should You Use?

Here's the quick version — if you have a tape measure, go with the US Navy Method. It's widely validated and only needs your neck and waist (and hips for women). If you have calipers, the Jackson/Pollock 3-site is a great starting point. If you just want a quick estimate with no tools, Heritage BMI is your fastest option.

Method Tools Needed Best For
Heritage BMI None (height + weight) Quick estimation, no tools
US Navy Tape measure (neck, waist, hips) Most accurate without calipers
YMCA Tape measure (waist) Simple, general fitness assessment
Jackson/Pollock 3‑site Caliper (3 sites) Accurate, good starting point with calipers
Jackson/Pollock 4‑site / 7‑site Caliper (4 or 7 sites) Most detailed, highest accuracy

Why I Made This (and Why You'll Actually Use It)

Here's the thing — I used to rely on those big fitness tracking apps. They work, but they're bloated, they want you to sign up, and honestly, I never felt great about entering my measurements into some database somewhere. So I built this. It's lightweight, it's fast, and everything stays on your machine. No data collection, no hidden fees, no "premium" features locked behind a paywall.

I've used this to track my own progress, help friends with their fitness goals, and just get a quick reality check on where I stand. It's one of those tools you don't think you need until you need it, and then you're really glad it exists.

Frequently Asked Questions

Is this body fat calculator really free?
Yes. No limits, no hidden fees, no watermarks. I built it because I needed it, and I figured other people might too. Use it as much as you want.
Do you store my measurements?
Nope. Your measurements never leave your browser. I don't upload them anywhere, I don't store them, I don't even see them. It's all local.
Which method is the most accurate?
The Jackson/Pollock caliper methods are generally considered the most accurate without lab equipment. The US Navy method is the best tape‑measure option. Heritage BMI is the least accurate but requires no tools.
What does my body fat percentage category mean?
The tool uses standard categories: Essential Fat, Typical Athletes, Fitness, Acceptable, and Obese. Each comes with a plain‑English explanation tailored to your sex.
Does this work on my phone?
It works on any modern browser — desktop, tablet, or phone. The interface adapts to your screen size.

Learn how to use this tool correctly by reading our step-by-step tutorial.

View Detailed Tutorial →