Dr. Andy Galpin

So what I mean by that is when you think about your body, if you want to globally say, okay, we're going to bucket everything into the amount of fat I have and the amount of nonfat I have.

That's not necessarily only muscle.

It includes things like water, muscle glycogen, bone, minerals, and things like that.

And so it's actually a pretty decent estimate of how much muscle you have, but not nearly as precise and specific as, again, some sort of MRI imaging could give you.

Now, in order to appropriately calculate these values, the best way is if you can get yourself into a DEXA scan or something like that.

Those are traditionally $100 to $200 or so available in America and plenty of other countries worldwide.

So a little bit less challenging and certainly more cost-friendly than the previous MRI stuff, but not free either, and so still may be outside of your cost range.

If you want to take a step below that, most home scales come with the ability to use what's called BIA.

And so this is effectively going to tell you your body fat percentage.

You can use that in combination with your height and get a rough estimate of your fat-free mass index.

Again, once you go down in the scale, scientific accuracy, you start to lose some fidelity of measurement.

But for a lot of people, that exchange of cost, difficulty, accessibility might be worth it, especially if you're just looking to see if you're close.

If you're trying to see whether or not you broke a world record, we probably need to go a little more accurate method.

But for those of you that are just trying to get a basic understanding of, am I significantly under-muscled?

Am I okay?

Where am I roughly at?

Those are absolutely fine metrics to take and to examine.

Fat-Free Mass Index, or FFMI, is probably the most established metric to look at here, so I'm going to focus mostly on that one.

Interesting enough, there is no fundamental way to calculate this.

There's a lot of nuance that can go into this that can alter your numbers in a decent amount of ways.