Updated: Nov 13, 2021
by Jonathon Sullivan MD, PhD, SSC, PBC
"I was told there would be no math."
I know this terrific guy, who’s a radiation oncologist. Think about that: this guy is part doctor, part physicist. That is one accomplished human being. Smart. A guy like that can do just about anything. Except, apparently, load a barbell correctly without difficulty. Upon his regularly failed attempts to do so, he would look at me sheepishly and say, “I was told there would be no math.”
I relate this anecdote only to point out a simple truth: just because you’re smart doesn’t mean loading the bar will come easy to you. Many smart people, especially at first, find it very challenging. If you think about it, it’s beyond mere arithmetic: your job is to load a prescribed weight with a limited number of plates occupying a limited number of discrete values, and to distribute that load symmetrically on a bar, while incorporating the weight of the bar in the entire prescribed load.
That is some serious next-level quantum field ectoplasmic fuzzy math science stuff. It’s a miracle anybody can do it. At bottom, it’s really just about finding the difference between what you have and what you want. Sadly, however, there are wrinkles. Fortunately, there is a very simple approach to this. For all I know, there are multiple very simple approaches to this, perhaps some even simpler than mine—although mine is pretty simple, because I can do it, and I’m not what anybody would call arithmetically gifted. If you are already good at bar loading, you might want to skip this—it could mess you up. Proceed at your own risk. Before we dive in, we have to know some basic stuff: First of all, you need to know what kind of plates you have: 45, 25, 10, 5, 2.5, 1.25, 1, ¾, ½, and ¼. All of these plates should be available to you. All of them. Without fail. A complete set of microplates is not optional. Note the absence of 35 lb. plates. Yes, we have them at Greysteel. We use them to keep the racks from sliding on the floor. It’s the only thing they’re good for. Your bar is 45 lbs. (or, in some cases, a 33 lb. or 15 lb. bar). Technically, the bar may be 20 kg, which is a little over 44 lbs., but most bars are not calibrated and most people (like me) are happy just calling all standard bars 45 lbs., because doing all this off a base of 44 lbs. leads to permanent neurological injury.
Next, you need to train your eye to spot common loading patterns that you will see in the wild all the time. When you see a bar with a 45 lb. plate and a 25 lb. plate on each side, you shouldn’t even have to calculate. You can, sure, and that will cover you, but ideally you should just know, without thinking, that it’s 185 lbs. Some common loading patterns are given in Figure 1. Know them.
Figure 1: Common bar loading patterns. Freedom units by Jonathon Sullivan; Rational Units by Victoria Volkov.
Okay, now it’s time to get down to cases. Here’s the way I think about loading the bar, presented in all its algorithmic glory:
Figure 2: The bar-loading process. Please note that there is no "FREAK OUT HERE" step. Stop and come back here, this second. I know that looks awful. But that’s because it’s an algorithm, and nobody ever painted an algorithm on the Sistine Chapel, or wrote a concerto about a process diagram. If you drew out an algorithm for something you do without thinking, like processing your mail or how to answer an innocent-sounding but dangerous question from your spouse, you’d come up with something every bit as imposing and ugly. You don’t use an explicit algorithm for your mail, or for your spouse (although you might want to think about that latter case). But this is math we’re talking about here. We’re trying to break the cycle of fear. When you work through this thing a few times, you’ll find that these are exactly the steps your brain needs to use to load a bar. The idea is to use it until you don’t need it, and loading the bar comes naturally. Climb the ladder, then kick it away. Most of these steps are self-explanatory. A few things, like “trading up” and “plate steps,” are best explained by examples. So here we go. Example 1: Let’s say we want to load 65 lbs on your bar. Let’s run the algorithm:
What is the current weight on the bar? Your bar is 45. That’s the current load.
Can you trade up plates? Since the bar has no plates yet, the answer is no. Onward.
What’s the difference between what’s on the bar and what you need to load? The difference between 45 and 65 is 20 lbs.
What is half of that difference (the half-difference)? The difference is 10 lbs.
Can the half-difference be loaded on each side with single available plates? Yes! 10 lb. plates are a thing!
Well, load it! Ten lb. plates. On both sides, please. This turns out to be important.
Done? Yep. Now you just have to lift it.
Easy! Let’s do another. Example 2: Let’s say your next set after 65 is 77.5 lbs.
What is the current weight on the bar? Your bar is at 65 from the last example.
Can you trade up plates? This is just asking if you can replace your biggest plate on the bar with the next biggest plate without going over. If you replace the 10 lb. plates with any other plate, you will be over or below your prescribed weight. So the answer is no.
What’s the difference between what’s on the bar and what you need to load? The difference is 12.5 lbs.
What is the half-difference? 6.25 lbs.
Can the half-difference be loaded on each side with single available plates? No! Because 6.25 lb. plates are not a thing. So now things are a bit less smooth than in the first example. No problem! Follow the algorithm to step 5a!
What is the largest plate step between what is on the bar and what you need to load? That’s easy to determine. The half-difference is 6.25 lbs, and the largest plate step beneath 6.25 lbs is 5 lbs. So let’s add 5 lbs to each side. Don’t think about the next step—just load it. Now we just re-enter the main algorithm at step 3!
3. What’s the difference between what’s NOW on the bar and what you need to load? The bar is now at 75 lbs, and you want 77.5, so the new difference is 2.5 lbs.
4. What’s the half-difference? Half of 2.5 is 1.25 lbs.
5. Can the half-difference be loaded with a pair of available plates? Yes! 1.25 lb. plates are a thing!
6. Well…load them!
7. Done? Yep. Lift it.
By now you should see that working through these examples verbally like this makes it seem a lot clunkier than it is. At bottom, the whole thing boils down to: a. Finding the half-difference between what you got and what you want, and b. finding the correct combination of plates to fit that half-difference…which is just a repeated application of finding the half-difference (including the 5a-to-3 loop), until you’re done! Let’s do a couple more, just to nail it home: Example 3: You’ve done your set at 77.5, and your next load is 89.
What is the current weight on the bar? Your bar is at 77.5.
Can you trade up plates? YES! If you take off the 1.25s and the 5s and replace them with 10s, you will have 85 lbs on the bar. You can see this option quickly if you just ask yourself whether the last few plates on the bar can be replaced with a bigger plate. If so, do so. Onward.
What is the new difference? 89-85 = 4 lbs.
What is the half-difference? 2 lbs.
Can the half-difference be loaded with a single pair of available plates? No. 2 lb. plates are not usually a thing. So it’s on to step 5a: what is the largest plate step between what is on the bar and what you need to load? The largest step is 1.25 lb. So we load that on each side, giving us 87.5 lbs. And back to step 3!
3. What’s the difference between what’s now on the bar and what you need to load? 89-87.5 = 1.5 lbs.
4. What’s the half-difference? 0.75 lb., which is (critically) three quarters of a pound, or ¾ lb.
5. Can the half-difference bet loaded with a single pair of available plates? Yes! ¾ lb. microplates are a thing! Unless you don’t have them, in which case you are boned!
6. Load them!
7. You’re done!
In the final example, I’ll show you how the previous example gives us a simple hack that allows us to avoid multiple iterations of the algorithm for numbers ending in 4 or 9. Check it out: Example 4: Your bar is loaded to 130. For some reason, your coach wants you to now load up 139.
What is the weight on the bar? 130.
Can you trade up plates? Yes! Unless you’re weird, your 45 lb. bar is loaded with a 25, a 10, a 5, and a 2.5 on each side (convince yourself that this must be true). But because you know common bar loading patterns, or even just because it occurs to you that each side of the bar is loaded with just shy of 45 lbs, you realize that if you trade up to 45 lb. plates on each side, you’ll have 135. So you do that.
What’s the difference between what is now on the bar and what you need to load? Here’s where the hack comes in. Last time, we needed to load eighty-nine, and we went through the 3-5a part of the algorithm a few times to solve it, eventually ending up with a 1.25 and a ¾ plate on each end to get us to the last 4 lbs. This will work any time the last digit is either a 4 or a nine. If we add 1.25 lb. + ¾ lb. plates to each side of a bar, we are adding four pounds, and that will get us the last step to 29, or 34, or 214, or 119, or whatever, without having to go through the entire algorithm. I have found this hack extremely useful, especially for movements like the press, where 1 lb. really makes a difference and the temptation to just round up to the next 5 or 10 is particularly ill-advised.
You may find this a bit clumsy at first—but no more clumsy than standing there with a bunch of plates in your hand, looking all like:
Just work with it a few times, and it will click, and you won’t need an algorithm anymore. Then you can concentrate on important things, like where you left your glasses and why your knee wraps keep sliding off.
Jonathon Sullivan MD, PhD, SSC, PBC is a retired emergency physician and research physiologist, and the owner and head coach of the Greysteel Strength and Conditioning Clinic in Farmington Hills, Michigan, which specializes in training adults over 50. He is the author of The Barbell Prescription: Strength Training for Life After Forty, with Coach Andy Baker.