It’s a popular practice among trainers to take body fat percent measurements. Whether it’s standing on the scale that tells you through pure sorcery or taking more measurements with tape than a coke addled tailor, you’ve come to expect it. However, I don’t do this and I discourage clients from doing it too. So, why do I shun the measuring tape or sending electrical currents through you to determine your body fat?

The first reason is that they’re notoriously inaccurate. How inaccurate, you might wonder? The gold standard, called a DEXA scan, is sometimes off by five percent in either direction. And that’s the best, most accurate method. Based on that, if somebody actually has 15 percent body fat, they can get a reading of anywhere from 10 to 20 percent. That’s a massive spread. For males, roughly 10 percent is where you start to look ripped and 20 is where you don’t even have faint outlines of abs. With things like skin calipers, you’d probably be just as well off spinning a wheel with numbers on it and going with whatever it lands on.

This brings me to the second reason I don’t measure people’s body fat percentages. It’s basically meaningless. If you need proof, think of the people for whom leanness matters the most: pro bodybuilders. They are not at all concerned with their body fat percent measurements. Instead, they worry about how lean they look. I’ve never heard of a panel of judges, after the contestant gets of stage, saying “You know, that guy looked phenomenal, but his body fat percent measurements were kind of high. Last place for him.” If these people aren’t using this measurement, then why would you? Last time I checked, the whole point is to look the way you want. If you’ve achieved that, who cares what the skin calipers are telling you.

While the third reason also goes for men, for the ladies an especially important issue is distribution of body fat. Two people can have the same body fat percentage, but carry it completely differently. It’s the equivalent of having two apartment buildings where the total income of the tenants is the same, but in one building they all make the same salary while in the other one person is extremely rich and everybody else is below the poverty line.

What is it that determines how your body fat is distributed? Unfortunately, genetics. Some ladies have the genetics that put most of their fat in the spots that make them look like hourglasses. We call these women like this “Scarlett Johansson.” Now, ladies, all stand in a circle and hold hands. Repeat after me, “I am not Scarlett Johansson.” Now that we’ve accepted this fact, you can get on with the business of looking your absolute best. Everybody’s different here. Through trial and error, you’ll find the weight/leanness where you’re the best, healthiest, most beautiful version of yourself possible. Remember “best” and “most beautiful” according to you, not some external judge that moves the goalposts. This also brings us back the the above point about “do you like how you look?”

So, now that I’ve completely flayed the idea of measuring body fat percentage, you’re probably wondering what I would have you use. Well, a good place to start would be your clothes. Can you now fit into those pants that used to be too tight? Are the sleeves of your shirts getting snug, but the waist feeling looser? Are you no longer wearing away the insides of the thighs on your jeans? If you answered yes to these questions, good things are happening in terms of fat loss.

Then there’s the obvious yet somehow overlooked “how do you look?” If, when you look in the mirror, you genuinely like how the person staring back looks, then you’re doing great no matter what the scale might say. If people you haven’t seen in a while are consistently commenting that you’ve lost weight, things are going well for you. My preferred method, though, is pictures in unflattering light. The light has to be unflattering because if you look better in that light, you’ll look awesome in good lighting. I’ll ask you to take before pictures. If you don’t want to let me see, that’s fine. But I do want you to take them so that you can have a reference point when we check back later. It’s very easy to miss the progress you’re making because, well, you see yourself every day in the mirror. I’ve had many people think they’re not getting better. Then we compare their current photo to the one they took when we first started. Jaws must often be scraped off the floor.

Lastly, you can go by feel. I mean this both literally and psychologically. If you grab your arm and, where once there was naught but flub, you now find firmness, this means you’ve packed on some muscle and lost some fat. Same goes for thighs and bums. If those parts used to jiggle while you walked and now they don’t, you’ve lost fat and added muscle. Rejoice! Other good indicators are psychological. Do you have more energy throughout the day? Can you now breeze through activities that once left you winded? Are you sleeping better? Though none of those will register on a scale or make the calipers say one thing or another, they’re a good indication that you’re dropping fat, putting on muscle, and overall healthier than before.

I do understand the desire to get a number. I’m all about numbers. The problem is that even our best methods are horribly inaccurate. People will often worry or feel terrible upon seeing these measurements. Though I don’t believe in lying to people just to make them feel better, this is a case where what you’d be told isn’t even the truth. It’s a very rough approximation that pales in comparison to other, more important measures, like comfort in your own skin or fitting into the clothes you were once too fat for. I don’t know about you, but I’d rather look better and have the body fat calculator tell me I’m “still 30%” than the other way around.