The 9 Best Ways to Measure Your Body Fat Percentage

If you’re working on your fitness, tracking body fat percentage can actually tell you more than just watching the scale

As a running coach, I’ve seen firsthand how understanding your body composition—specifically fat versus muscle mass—can give you a clearer picture of your fitness progress.

So, why bother with body composition tracking?

Exercise, especially strength training, can really add muscle

So, while the scale may not budge, you might actually be making big changes to your body composition. That’s why monitoring your fat-to-muscle ratio gives a more accurate picture of your progress than just looking at your weight.

In this article, we’ll dive into body fat percentage, why it matters, and the best ways to measure it.

What Is Body Fat Percentage?

Body fat percentage tells you how much of your weight is fat versus everything else. The metric has nothing to do with your muscle mass, so two people with similar body fat percentages can look completely different.

In other words, it’s the amount of fat in your entire body compared to everything else, such as your:

• Muscles
• Bones
• Organs
• Tendons
• Ligaments
• Water

For example, if you weigh 180 pounds and have 35 pounds of fat, your body fat percentage would be 19% (35 ÷ 180). Even if your weight stays the same, reducing fat and increasing muscle will improve your overall body composition.

Age, gender, genetics, and activity level significantly determine your ideal body fat percentage. Generally, men and women have different targets. Men may aim for 10-20% body fat, while women often aim for 18-28% due to physiological differences.

Why Track Your Fat-to-muscle Ratio?

Body fat percentage isn’t a vanity marker; it’s actually an important health marker. I’ve coached athletes who felt discouraged by their weight on the scale, only to realize that they were building muscle and losing fat at the same time.

Let me explain more:

• More accurate progress tracking helps you see if you’re losing fat, gaining muscle, or both.
• Setting realistic goals: Knowing how much fat you need to lose (or gain) can make goal-setting easier.
• Improving health awareness: A high body fat percentage increases the risk of heart disease, diabetes, and high blood pressure.

Body fat percentage can tell you way more about your fitness progress than a scale. I get it—it’s easy to obsess over weight, but your body composition tells the story of your fitness progress.

So, let’s talk about how to measure body fat. I’ll walk you through seven common methods, from simple and affordable to the highly accurate.

1. Check Your Progress with Photos and the Mirror

This is it if you’re looking for an easy way to estimate your body fat without fancy tools. I know it’s not scientific, but progress photos are a super simple way to actually see your fat loss.

• How It Works: Take weekly or monthly photos from the front, side, and back, wearing the same outfit each time. Stand in the same spot, ideally in front of a plain background with good lighting. Over time, these photos will show changes the scale might miss—especially if you lose fat and gain muscle.
• Accuracy: Let’s be real, it’s not the most accurate method. You won’t get an exact number for your body fat percentage, but it’s great for monitoring your progress. Pictures don’t lie—they’ll show your progress clearly.
• My Best Tip: I’ve seen this work wonders for many clients. Have a friend or partner snap the pics so you’re not fumbling with your phone. And trust me, the consistency of timing and lighting makes all the difference when you compare photos later.

2. Waist Measurements

Carrying fat around your waist can be more than just an aesthetic issue—it’s also a health indicator. Belly fat is linked to higher risks of diseases like diabetes and heart problems, even in people who otherwise seem healthy.

• How It Works: Use a measuring tape to track your waist circumference around your belly button. Also, measure other areas like your hips or thighs for a fuller picture.
• Accuracy: It’s not a direct measure of body fat but can be a good indicator of progress. For men, a waist measurement over 40 inches and women, over 35 inches, can indicate a higher risk of health issues.
• My Best Tip: Once I started tracking my waist measurement, I was surprised by how much it showed about my health. Just measure the same spot every time to ensure consistent results.

3. Skinfold Calipers

Skinfold calipers are a popular tool among trainers for estimating body fat. I remember trying them the first time—I had no idea what I was doing. But with practice, this method became one of my go-to tools for clients.

• How It Works: Calipers pinch the skin at specific sites to measure the thickness of the fat underneath. Typically, measurements are taken at the abdomen, thigh, and arm, then plugged into a formula to estimate body fat percentage.
• Accuracy: When done correctly, calipers can be accurate within 3-5%, but the key word is correctly. If you’re new to calipers, ask someone with experience to help, as it’s tricky to do on your own.
• My Best Tip: Have the same person take your measurements every time to minimize errors. I always measure clients on the same side of the body and average three readings at each site to get the most reliable estimate.

4. DEXA Scan

If you’re after precision, the DEXA scan is as good as it gets.. I’ve done this myself, and while it’s not something you can do every day, it’s the gold standard for measuring body composition.

• How It Works: During a DEXA scan, you lie still on a table while an X-ray machine scans your body. The scan differentiates between fat, muscle, and bone, providing a complete picture of your body composition.
• Accuracy: DEXA scans are incredibly accurate, with an error margin of only 2-3%. It’s also great for tracking where you lose or gain fat and muscle.
• My Best Tip: The downside? It’s expensive and not always easy to find. Expect to pay around $100-150 for a scan, but it’s worth the investment if you’re serious about tracking body composition.

5. Hydrostatic Weighing

Also known as underwater weighing, hydrostatic weighing has been around for decades and is another highly accurate method to measure body fat. I tried it once and felt like I was taking a deep dive into science.

• How It Works: You’re weighed on land and submerged in water. Since muscle is denser than fat, you’ll weigh less underwater if you have more fat.
• Accuracy: With an error margin of around 2%, this is one of the most accurate methods available. However, it’s not as widely accessible and can be uncomfortable for people who don’t like being underwater.
• My Best Tip: If you use this method, ensure you can fully exhale all the air from your lungs while underwater. It’s crucial for getting an accurate result.

6. Bod Pod

The Bod Pod is like something out of a sci-fi movie. It uses air displacement to measure your body composition and is quick, safe, and non-invasive. I’ve seen a few clients opt for this method, and it’s been a reliable option for tracking progress.

• How It Works: You sit inside a small, egg-shaped chamber while the machine measures how much air your body displaces. This data is used to calculate your body fat percentage.
• Accuracy: The Bod Pod has an error rate of about 1-2.7%, which puts it in the same league as hydrostatic weighing.
• My Best Tip: It’s not available everywhere, but if you can find a facility with a Bod Pod, it’s a convenient way to get a highly accurate body fat measurement without getting wet or exposed to radiation.

7. Bioelectrical Impedance Analysis (BIA)

BIA is often found in smart scales and handheld devices. It works by sending a small electrical current through your body, and since muscle conducts electricity better than fat, the device estimates your body fat percentage based on the resistance.

• How It Works: You either stand on a scale or hold a handheld device that sends the current through your body. It’s quick, easy, and can be done at home.
• Accuracy: BIA’s accuracy can vary depending on factors like hydration, with a 3-5% margin of error.
• My Best Tip: Measure first thing in the morning before you’ve had anything to eat or drink. Hydration can throw off the results, so consistency is key.

Conclusion

Tracking your body composition is a powerful way to monitor your fitness journey, whether your goal is fat loss, muscle gain, or simply maintaining optimal health. For many, a combination of methods—such as photos, waist measurements, and skin calipers—can provide a well-rounded view of your progress.

DEXA scans or Bod Pods are excellent options for those seeking the most accurate results, though they can be costly and harder to access. However, simpler methods like calipers and BIA scales can effectively track changes over time and are much more practical for regular use.

No matter which method you choose, consistency is key.

Track your body fat regularly under the same conditions to get the most accurate picture of your progress.

And remember, it’s not just about the numbers—it’s about how you feel and your body performs.