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The Different PC Case Sizes Explained: From Full Tower to Mini ITX Cases

PC case sizes. No one ever talks about them. They’re boring, they’re simple, and a lot of people they’re nothing more than just housing for all your PC hardware. A PC case is as insignificant as that protective case that you have on your phone.

But it’s far from the actual truth. PC cases are just as complicated and just as crucial when it comes to building a powerful gaming PC. A PC case can make or break your entire build because not all cases are made equal. Believe us when we say that there’s a lot of terminologies to memorize and learn when it comes to understanding how PC cases play a role in building custom PCs.

If you’re reading this article, chances are you’re a first-time buyer or PC builder who needs a new PC case to upgrade their current custom PC build, or looking to get started with building.

What is a Computer or PC Case?

A Computer Case, or PC case, protects the internal hardware and provides structure for the computer. The sizes and form factor of the PC will determine what hardware goes inside.

That’s right. Your computer’s case size will tell you what hardware you can install and can’t install. When it comes to building a custom PC, knowing if you have enough space or not is crucial.

There are two important functions highlighted in any PC case:

  • Ventilation and cooling support – Apart from managing air flow, your PC case can accommodate additional ventilation and cooling features such as bigger fans and liquid cooling systems. Even if you don’t have liquid cooling on your PC, air circulation is still important to keep your unit cool.
  • Protection from external damages – A PC case, no matter what size you get, is rigid enough to withstand small bumps to prevent damage to the internal hardware. Worst case scenario, your entire rig falls off the table. Your PC case should be able to minimize damage to the hardware (i.e. CPU, GPU, fans, etc.), but there’s no guarantee that these components won’t be unscathed either.

What Are The Different PC Cases?

Size matters. At least for PC cases. PC cases should have enough space to accommodate and protect hardware such as GPU, HDD/SDD, CPUs, and so on. Without proper air circulation or if your case doesn’t have cooling fans, overheating will damage these components.

The size of your computer cases and the build of the computer itself should both be compatible with one another. This section should go over important aspects of computer case size comparison and what sizes are best for which functionality.

Full Tower Case

Motherboard Form Factor: Extended ATX (or E ATX) or Standard ATX

Most custom gaming PC enthusiasts would often go for a full tower case as their main choice for PC case size. Full tower computer cases can accommodate any E ATX or SSI CEB-sized motherboard and have a lot of expansion compatibility. There’s also improved thermal performance, but does not apply to all full tower cases in the market.

Apart from gamers, people who are building their own servers choose a full tower case with extended ATX because it can accommodate extra RAM and CPU . Then you also have those overclocking enthusiasts who need a lot of cooling to quickly dissipate heat when certain components such as CPU and GPU are pushed to the limits. To make this possible, they need to equip the PC with triple heat sinks, CPU cooler, water cooling, and big radiators. And these components aren’t exactly small and portable.

It’s also possible to install multiple GPUs using SLI and crossfire with a full tower case, or even install large GPUs thanks to vertical GPU mounting. An RTX 3090 Gaming PC would also use full tower cases just for the sheer size of the GPU.

Motherboard Form Factor PC Case Sizes

Mid Tower Case

Motherboard Form Factor: ATX or Micro ATX

Mid towers offer the most flexibility for PC builders because they’re smaller and more compact, but capable of equipping standard ATX motherboards or micro ATX motherboards. The cases can also accommodate LED lighting and added cooling fans for those who want to show off some RGB swag.

Similar to full towers, mid tower computer cases are able to support two graphics cards. Some can even accommodate up to three graphics cards. But most builders won’t even add a second or third GPU because they just want to take advantage of the PCI-e slots for later expansions down the line. For example, installing a 2080Ti takes up a couple of PCIe slots on the motherboard. You could make it work with a mid tower, but if you want to add in a second GPU with your 2080Ti, then just go for the full tower case

It goes without saying that mid tower cases are smaller than full towers, so you get more desk space but you do get increased ambient temperatures when you’re running the rig. Mid towers can’t install as much CPU fans as a full tower, so there’s less air flow and reduced air circulation.

But air flow is just the tip of the iceberg for many mid tower cases. A mid tower offers lesser space for optimal cable management, less HDD support, and unable to equip large liquid-cooling configs. Overclocking is out of the question for a mid tower. But if that’s not your end goal for building a custom PC and just want something compact on your desk, then a Mid Tower might be worth considering.

Mini Tower

Motherboard Form Factor: Mini-ITX or Micro-ATX

Smaller cases accommodate small form factor motherboards, namely mini ITX or Micro ATX. Mini tower cases have risen in popularity for their unique tempered glass design, affordability, and ability to accommodate other small form factor components. We’re talking about using a low profile GPU with subtle cooling configs.

But not all mini tower cases are equal. Sure, they can accommodate smaller micro ATX motherboards, but that’s not really a big deciding factor. You have less spaces for HDD and less expansion slots, and you might not be able to accommodate large GPUs because of clearance issues.

Smaller Form Factor

Motherboard Form Factor: Mini-ITX

The smallest computer case of them all, the small form factor case is not to be underestimated. Despite its size, there are computer builders out there who’re pumping out high-end builds with just a mini ITX motherboard.

The smaller form factor cases are great for people who just want a minimalistic gaming station or workstation.

What Features Do You Want When Shopping for Computer Cases?

Now that we’ve gotten the computer case size comparison out of the way, it’s time to talk about PC case features. Size affects what features you’re getting on a case, such as a bigger motherboard tray, custom loop support, case fans, drive bays, and so on.

Here’s what you need to know about features that are affected by computer case sizes:

Drive Mounting – Drive mounting is an important factor to consider because you’re looking at hard drive space. Your new PC case should have enough room for 2.5″ HDD or 3.5″ HDD, or even 5.25″ HDD drives that you’re using.

There are cases in the market that have the right mounting space directly on the motherboard tray’s sheet metal. You’ll want to look for four holes where you can screw the drive in. There are also other cases that have a removable caddy that will allow you to access all your installed drives easily. Think of it as a plug-and-play feature, but on your PC case.

Water-cooling features – Custom loop water cooling will always be the best option for PC cooling, no matter what people say. To make this possible, you need a radiator. But this isn’t going to fit into a mini ITX case or a smaller form factor case. You need a PC case that can accommodate hardware of this size, and that’s going to be a full tower case. You’ll be lucky to find a mid tower case that can fit a radiator or custom loops too, but they’re not that uncommon.

Cable ManagementMini ITX cases and smaller form factor cases might not have the best options for cable management because there’s not enough space. How much space you have on your PC case will determine your ability to manage cables. If you’re particular about how your cabling should look like, a full tower case is the best option.

Toolless design – High end PC cases often have a toolless design, which is a modern design aspect done by case manufacturers. These are features that make your life easier as a PC user. You just remove one screw from a clip-on drive bay and you can easily access your hardware. Other toolless design features are motherboard cut-out covers, removable PSU shrouds, and hard drive caddies.

Motherboards Are Linked To Computer Case Sizing

PC building is more than just knowing what size of PC case to use. You also need to consider the size of the motherboard that could fit into the PC case you want to use.

Motherboards come with different sizes or form factors. Smaller motherboards go well with smaller cases, and larger motherboards go with large cases.

There are three main form factors:

  • Mini ITX
  • Micro ATX
  • ATX

Full tower cases can accommodate E ATX and Micro ATX motherboards (largest and smallest form factor motherboards respectively). Mid towers can handle standard ATX and Micro ATX motherboards. Mini towers can accommodate Micro ATX and Mini ITX. Smaller Form Factors can only accommodate Mini ITX motherboards.

Size doesn’t really matter in terms of performance because you’ll find that each form factor has the best motherboards. Smaller motherboards will have fewer PCIe slots, storage expansion ports, and RAM slots. Opting for a smaller motherboard means you’re willing to sacrifice your ability for upgrade or expansion.

What’s The Best Cast Size for Hardcore Gamers?

We’ll consider three factors when it comes to choosing the best case size for hardcore gaming.

If You Want to Build a Small Size PC

Small Form PC Case Sizes

If you want something small on your desktop, the Phanteks Evolv Shift 2 is the best mini ITX case that offers flexibility and extreme versatility. This is great for gamers who want to go to LAN parties a lot.

Ideally, you want a small case that can support micro ATX motherboards because of the slots available. But if you really want the smallest size possible, you could work with an SFF (Smaller Form FactorS) case. You’ll end up spending more money because a mini ITX motherboard is expensive but with fewer capabilities. You’re also going for small form factor cooling hardware and PSU.

If possible, stretch your budget so you can purchase mini ITX cases. At least you’re getting some value out of the size. With a case like this, your gaming PC would probably be put together for less than $1000.

For Those Who Don’t Care About Size

Dark Base Pro 900 PC Case Size

If you don’t really mind looking at a humungous piece of PC in your room, go for be quiet!’s Dark Base Pro 900, a full tower case with a lot of potential room for upgrades. You want to get this case because there’s a lot of room for hardware, more RAM, PCI-e card expansion slots, and storage expansion.

You also get to enjoy larger cooling solutions and better air circulation thanks to the added fans you can install.

An ATX motherboard in a full tower case gives you all the flexibility you need for upgrading in the future. But if a budget PC is what you’re aiming for, consider a micro ATX board to go with a full tower case.

If You’re Fine With Spending A Lot of Money

Thermaltake Core P8 PC Case Size

You want to go all out with this one, so E ATX motherboards are definitely the way to go with a full tower case. You might even go for an Ultra Tower with E ATX motherboard. A good option to go here would be the Thermal Take Core P8, a huge lunk of a case with great EATX mobo support. Prebuilt gaming PCs would often use cases that accommodate E ATX motherboards (we’re looking at you, Alienware).

Size of the case and price of the case won’t even be part of the equation anymore because you just want a PC case to give you a lot of options for upgrade and expansion. And an E ATX motherboard can give you that.

If you do decide to go with an ultra tower case, know that these cases are very heavy and large. You might not be able to move them easily too. But if you want to bring along your expensive PC, just go for a full tower with regular ATX mobo.

Best Bang for Your Buck

Lian Li 205M PC Case Size

If you want the best bang for your buck, consider the micro-ATX Lian Li 205M. This is the best option for those working on a tight budget. You could also consider a micro ATX motherboard to go with a mid tower.

Micro ATX motherboards may have a couple of PCI-e slots with x16 lanes, which is more than enough for most gamers. They also have four RAM slots with NVMe storage capability. Upgrading and expanding is not really a challenge here with a micro ATX motherboard. You might be able to use this for $600 gaming PC budget builds too.

Mid tower cases can also get you enough space to host large cooling solutions with enough cable management options.


Now you know everything there is to know about different sizes for computer cases. You know what most common form factor motherboards should go with whatever the size of computer case you want to purchase.

Ultimately, it will boil down to what you’re willing to spend on, and what your aesthetic tastes will be like in deciding which size of computer cases will be right for you.

James Stephenson

james stephenson profile picJames is a gaming and tech enthusiast. He has been playing computer games since the Commodore 64 days in the 80s. He has worked as a Broadcast Engineer with BBC News and knows a thing or two about building, fixing, and playing with PCs.