A micro ATX is physically compatible with an ATX case without any problems whatsoever. But it looks a bit weird as the ATX case is much larger than the micro ATX case in real life. However, the mismatched size won’t hamper your operating system by any means.
In addition, this compatibility provides a few additional benefits that we have discussed later on. So, if you are willing to know more, going through this article will pay off.

Table of Contents
Do All Motherboards Fit in Any Case?
No, all motherboards do not fit in any given case. Different motherboard cases have a variety of standoff mounts. Therefore, you cannot but find an appropriate one for placing your motherboard.
For example, an ATX motherboard cannot fit in a Mini Tower PC case. Generally, ATX motherboards require a case that is fully compatible in order to provide a smooth operation.
Does Micro ATX Fit in ATX Case?
Are you worried about whether or not your micro ATX fits in an ATX case? The straightforward answer to this question is yes. Micro-ATX motherboards are physically compatible with ATX cases, as they share most of the same mounting holes as full-size ATX boards.
But you may find differences in the bottom row. To clarify, the bottom part of the micro-ATX is 9.6 inches, while the ATX is almost 12 inches.
Not all but most of the mid and full-tower ATX cases have the correct standoff mounts for micro-ATX’s bottom row. Even if your case does not, there are six mounting holes- C, H, L, F, J, and M. They can be shared between Micro-ATX and ATX when your case does not support specific mounting holes for micro-ATX.
When you try to place a micro-ATX on an ATX case, it obviously leaves some empty slots. Do not bother if the bottom is not exactly in the right place. Because the top portion will get placed perfectly regardless of motherboard size. And that itself is enough for proper functioning.

Pros of Using an ATX Case for a Micro-ATX
There is always confusion regarding whether or not things will smoothly operate when you use an ATX case for a micro-ATX. But interestingly, it does not hamper micro-ATX’s functioning capability. Instead, it even provides you with some advantages. For example, your PC will get better airflow with more room for upgrades.
Moreover, as micro ATX does not use the entire space of a full-size case, you can use it for drive bays, water components, internal USB, and so on.
In fact, it is the best bet when you want to transplant to an ATX board. Because if you use a micro-ATX case for a micro-ATX motherboard, you have to replace it while upgrading it with ATX. So, it lessens your future cost.
Cons of Using an ATX Case for a Micro-ATX
The only disadvantage is the size of the case. As the ATX case is much larger, micro-ATX may seem diminutive. Besides, sometimes the case comes with a window which makes the interior visible.
But, as this window only focuses on the top, no one would find out which size of the motherboard is inside. Interestingly, if you light the motherboard area and leave the rest of the cast in shadow, it would make the size of the motherboard less noticeable.
Are all micro-ATX motherboards the same size?
No, all micro-ATX are not of the same size. Nevertheless, most will have the same width, but the length varies from unit to unit.
Final Words
So, it turns out that you can easily fit Micro-ATX in an ATX case. And it will not hamper the functionalities of either of them. But it leaves some unused space which may affect the overall aesthetics. Yet, it is often okay to trade off the external appearance of a computer in exchange for a smooth performance.