Anna Victoria has made it clear she’s not a fan of scales. The superstar fitness blogger and trainer doesn’t weigh herself, and urges her followers not to obsess over how much they weigh either. 

Victoria’s onto something: A scale can tell you your total weight, sure, but it can’t tell you much more. It won’t reflect how much muscle you’ve gained thanks to a new strength training routine, or how much fat you’ve lost after making healthy diet swaps.

Instead, Victoria recommends finding out how much body fat you’re carrying around, and then tracking that number monthly. You can do so with body composition tests, which reveal how much of your total weight is fat compared to muscle, bone, and water. These tests can be done with at-home gadgets, or devices at fitness centers—or with more high-tech machines at weight loss clinics and research facilities.

In a new YouTube video, Victoria, who’s no stranger to baring all online, set out to measure her body composition using a bunch of different tests or tools–and got six different results, ranging from 14.2% to 26.4% body fat.

The lowest result surprised her, she says in the video, but hardcore female athletes are often in the body fat percentage range of 14% to 20%. Everyday exercisers are typically around 21% to 24% fat, while women with a body fat percentage of 32% and higher are considered obese, according to the American Council on Exercise. (Male athletes are usually around 6% to 13% fat, while men with 25% body fat or higher are considered obese.)

RELATED: 13 Best (and Worst) Ways to Measure Body Fat

There’s research to suggest that body fat percentage is actually a better measure of health than the number on the scale. A 2016 showed that people with more body fat were more likely to die early than people with less fat, regardless of how much they weighed. The good news is that your percent body fat is totally modifiable, says John A. Shepherd, PhD, director of the Body Composition, Exercise Physiology, and Energy Metabolism Laboratory at the University of California San Francisco. 

“Body composition is one of the most modifiable risk factors we have for many common diseases, including diabetes, cardiovascular disease, and even cancer,” he explains. “A lot of our disease risk factors–like genetic risk factors or family history–you can’t do anything about.” It’s worth knowing your body fat percentage, he says, so you can be aware of how it might affect your health–and then get to work changing it.

So how do you measure your body composition? Here are the six methods Victoria tried, and her surprisingly variable results.

Hydrostatic weighing

This test involves expelling all the air from your lungs and then being submerged in water. The water displacement gives your technician an idea of how much of your body is fat compared to lean mass. Yes, hydrostatic weighing is as inconvenient as it sounds—and it’s not all that easy to find a facility to perform this test, either.
Victoria’s results: 14.2%

Bioeletrical Impedance Analysis (BIA)

BIA machines send an electrical current through your body (don’t worry, you don’t feel a thing) to measure fat. The technology can be extremely accurate when used in a weight-loss lab setting, but at-home scales and handheld devices you might remember from gym class aren’t always so spot-on.
Victoria’s results: 26.1% on her BIA scale at home; 18.8% on a handheld device at a gym

Calipers

The classic “pinch test” involves measuring how much of you is pinchable in different spots on your body, like your belly and thighs. Well-trained professionals can be pretty accurate with these devices.
Victoria’s results: 23.4%

DEXA Scan

Dual-energy X-ray absorptiometry is typically used to measure bone density, but can be used to examine muscle and fat, too. A DEXA scan is considered the gold standard of body composition testing.
Victoria’s results: 23.5%

Bod Pod

The most expensive option, this space-age-looking pod works similarly to hydrostatic weighing but uses air displacement instead of water to calculate your lean and fat mass.
Victoria’s results: 26.4%

To get more fitness tips, sign up for the Health newsletter

So, how could one incredibly fit woman have such a range of results?

The testing methods often use different calculations to arrive at their final percentages, explains Shepherd, so it’s not totally off-base for various methods to produce a range of results. But, he warns, there’s also a chance at-home devices aren’t as accurate as machines used in professional settings.

Your best bet is to stick with just one testing method and focus on how your results change over time. That will allow you to compare your numbers from month to month better than if you were comparing the results from different testing methods, Victoria says.

Shepherd agrees: “You can use home technology to monitor changes in body fat, even though the absolute value might be off,” he says.

The method you ultimately choose will likely depend on where you live—since you may not have easy access to all these tests—as well as your budget. Victoria paid between $45 and $95 for her six measurements, but prices can vary. She also points out that it’s important to keep other variables similar too, like measuring your body composition around the same time of day each time, or having the same trainer operate the calipers for you.

Seeing the progress you’re making can be a powerful thing: “How much you weigh is not what is important,” she says in her video. “What is important is that you are working hard to be your very, very best, every single day.”