I trained at commercial gyms for many years before building my garage gym. In those years, I rarely questioned the available equipment.
Whatever was there was good enough for me.
So when I started shopping for equipment for my garage gym, I was shocked at all of the options for seemingly simple things. Barbells, in particular, were a much more involved purchase than I had thought.
One of the most confusing aspects was barbell diameter. Should I get a 25mm, 28mm, 28.5mm, or 29mm bar? I only wanted to buy one barbell, so which one is best?
Out of all the barbell specs, bar diameter is one that actually matters. It makes a difference in several ways. But that doesn’t mean it needs to make your barbell selection more difficult.
Table of Contents
What’s The Best Barbell Diameter For A Garage Gym?
The best barbell diameter is determined by how you will be using your barbell. 25mm is appropriate for women, kids, or anyone with very small hands. 28-28.5mm are usually reserved for those doing Olympic lifting. 29mm is the best choice for power bars. Other diameters are rare and very use-specific.
|Bar Diameter||Bar Use|
|25mm||Women, Kids, Men who can’t use a larger bar|
The nice thing about how this works is that if you know the type of lifting you’ll be doing and buy a bar made for that, you will, by default, end up with the appropriate diameter bar.
Any quality barbell manufacturer will use the correct diameter bar stock to make bars for those specific purposes. Usually, only the no-name bars you find on Amazon or at your local big-box sporting goods store get this wrong.
And since you should never buy one of those barbells anyway, let’s stick to those made by quality companies.
If You Are Building A Home Gym, Buy This Diameter Barbell
95% of the time, when someone asks me what kind of barbell to buy, I tell them to buy a power bar. Power bars are usually 29mm in diameter.
If you are reading this article because you were shopping for barbells, saw different diameters listed, and wondered which was best, the answer is a 29mm power bar.
The only people I ever recommend a different type of barbell to are highly experienced Olympic lifters (who already know about bar diameter) or folks who can’t physically train with a 20kg bar yet.
Most people will never be able to tell the difference between two bars of different diameters. Most people also can’t even lift enough weight ever to tell the difference.
Don’t let deciding on bar diameter delay your training.
If you need a recommendation, I keep a fully updated page of barbell recommendations here for your reference!
How Does Barbell Diameter Impact A Barbell?
A bar’s diameter impacts three primary characteristics:
By manipulating each of those qualities, a bar can be made to suit specific lifting goals better.
A smaller diameter bar will weigh less than a larger one. A lighter barbell is advantageous when building barbells for women, kids, and folks starting with lower levels of strength.
Smaller diameter bars will also have more potential for bar whip. I put together a full explanation of barbell whip that you can read here, but basically, the thinner the bar, the more it will flex under load.
This flex benefits experienced lifters doing the deadlift, snatch, and clean & jerk.
Larger diameter bars are stiffer with less flex. A rigid bar lends itself to traditional barbell movements like presses, squats, and rows.
The last variable is one I personally appreciate very much. I’m 6’6″ and 230 lbs. with giant hands. Larger diameter bars fit my grip much better than narrower bars.
For others with smaller hands (typically women and kids), a smaller diameter bar may be more comfortable.
When To Buy A 25mm Barbell
If you are a smaller framed person (I prefer looking at it that way instead of pigeon-holing women and kids into this diameter barbell), you may want a 15kg bar instead of a 20kg bar.
While this size bar is typically called a women’s bar, it can be a lifesaver for men who aren’t as strong as others or are simply smaller people with smaller hands.
If a standard 20kg barbell feels too big for your hands or is too heavy to use, consider a 15kg bar. By default, you’ll usually be getting a 25mm diameter.
This 15kg Colorado bar from Rep Fitness is an excellent example of a 25mm bar.
Another less common use case for 25mm barbells is in a dedicated deadlifting bar like the Hades deadlift bar by Rep Fitness. The extra flex and whip provided by the slimmer bar assist experienced deadlifters in lifting more weight.
When To Buy A 28mm Barbell
28mm barbells are typically built for Olympic lifting. The added whip of a 28mm bar (vs. the 29mm found in most powerlifting bars) can aid an experienced lifter in competition.
While there are a few power bars out there that come in a 28mm diameter, they are not common.
If you will be Olympic lifting (the snatch and the clean & press), get a 28mm Olympic lifting bar.
If you are not, you can pass on this diameter.
When To Buy A 28.5mm Barbell
28.5mm barbells are usually classified as “multi-purpose” barbells. That’s also the most common diameter of Cross Fit specific bars.
If you belong to a CrossFit box and are buying a barbell to use at home, it’s best to match the barbell diameter used in your box. That will usually be 28.5mm.
The idea is that you want to train with the same gear you’ll be competing with.
If this is not you, skip the “multi-purpose” bars. It’s an easy trap to fall into as most people building a home gym plan on doing multi-purpose training.
But as with most folks, you are better off with a 29mm power bar if you don’t have a particular need for something else.
When To Buy A 29mm Barbell
Unless you fall into one of the exceptions above, you will most likely be best served by a 29mm barbell.
29mm is the most common diameter of power bars, and power bars are, in my opinion, the perfect option for most home gym owners. I wrote a very complete article here that explains why in detail.
A bar of this diameter won’t impede any type of lifting either. You can perform virtually any lift with a 29mm barbell.
What About 32mm or Larger Barbells?
The above-listed diameters aren’t inclusive of every available option but are the most common.
Occasionally, you’ll find larger diameters. These are always for specialty bars like the Helios squat bar by Rep Fitness. The thickness of this 32mm diameter barbell creates a stiff, whip-free barbell ideal for squatting.
Virtually any time you see a barbell thicker than 29mm, it will have been built for a specific lift or purpose outside general training.
Let’s be honest and take a quick step back.
Most people will never be able to tell a functional difference between different diameter barbells. If you were to go down to your local gym and swap all the 29mm barbells with 28mm barbells, odds are no one would ever know.
So, if you’ve found a good deal or a barbell that you really like and feels great in your hands, go for it! Don’t let that bar’s diameter be the one thing to dissuade you.
But, if you haven’t landed on a bar you like yet, definitely consider barbell diameter before purchasing. As you gain experience, you will also gain an appreciation for matching your barbell’s diameter to the type of lifting you will be doing.
I lift competitively. Does bar diameter matter to me?
Yes! Anyone lifting competitively should aim to use the same bar when training at home as in competition. This includes matching bar diameter!
Can you buy the wrong diameter?
For general training and fitness, if you stay within the 25mm to 29mm range, odds are you’ll be just fine. Even though a bar may not be “ideal” for you, it will still work great regardless of its diameter.
If you are an experienced lifter looking for a bar that aids in your training, I would advise paying attention to the bar diameter.
You say not to use a multi-purpose bar for most home gyms, but that seems like it would make the most sense.
I fell into the same trap when I first built my garage gym. Remember that the “multi-purpose” name implies you’ll be doing a lot of Olympic lifting in addition to powerlifting movements.
Most people are not and should not be doing Olympic lifting at home. For this reason, a multi-purpose (CrossFit) bar isn’t needed or advantageous.