Aren’t all PC cases the same size case and why would a PC case size matter in the first place? Well, there is much more to PC case sizes than you imagined.
Selecting the right size case for the PC is like like putting up a strong foundation for the rest of the components to build upon. The size of the PC case dictates what specs your PC will end up having. As a result, if you mess up this step of the process, the rest of the PC build will not be able to realize its full potential.
To select the right PC case, you need to know the pitfalls of each case size. Along with that, it is also important to understand the benefits and drawbacks that each case size brings to the table to make a more informed decision.
There is a lot to understand, so without further ado, let’s jump straight into the definitive guide on PC case size.
PC Case Sizes
A PC case comes in four different sizes, those being: Small Form Factor (SFF), Mini Tower, Mid Tower, and Full Tower, in order of smallest to largest.
There are no hard stuck rules regarding the exact dimensions a case in a given size category must abide by.
The dimensions are loosely based on a general size every manufacturer thinks is the best for their case. A small form factor (SFF) case measures 8-10 inches, a mini tower case 11-14 inches, a mid tower case 14-20, and a full tower case can go up to 27 inches from the ground.
To be recognized as a small form factor (SFF), mini tower, mid tower, and full tower, a PC case has to satisfy some other requirement besides the size. These requirements, such as support for the motherboard size, support for different case fan sizes, the number of dive bays, and total expansion slots, can hold a lot of weight in determining which category a case belongs to.

That is especially true for mid tower and full tower cases. The size of both of these cases is not miles apart, and it is hard to know which case is which solely by looking at them because the difference of a few inches is hard to perceive unless they are put side by side. So to differentiate among these cases, the other attributes help greatly.
Small Form Factor | Mini Tower | Mid Tower | Full Tower | |
Motherboards | Mini-ITX | Mini-ITX MicroATX | Mini-ITX MicroATX ATX | Mini-ITX MicroATX ATX EATX |
5.25″ Drive Bays | 1 | 1 to 2 | 2 to 5 | 3 to 6 |
3.5″ Drive Bays | 1 to 3 | 4 to 6 | 6 to 8 | 6 to 13 |
2.5″ Drive Bays | 0 to 4 | 0 to 4 | 0 to 10 | 0 to 11 |
Expansion Slots | 2 | 4 | 7 to 8 | 7 to 10 |
Graphics Cards | 1 | 1 to 2 | 2 to 3 | 3 to 4 |
Case Fans | 1 to 3 | 2 to 4 | 3 to 9 | 5 to 10 |
Small form Factor
Advantages of Small Form Factor
The main advantage of the small form factor case is its portability. The compact size of the PC case allows users to easily carry it with them because it can be easily tucked away in a backpack or inside the briefcase. The small size also means that this PC case can be used anywhere, whether it may be on your main desk or on a tabletop in a cafe, if you so desire. It doesn’t stand out and can easily fit in, unlike the larger PC cases.
Disadvantages of Small Form Factor
The biggest drawback of the small form factor case is its limited PC airflow. The small size of the case means that there are few air channels for air getting into and out of the case. As a result, PCs built with small form factor cases tend to overheat.
Another plausible drawback of this size of the case is the lack of user-friendly options. What I mean by that is this case is very difficult to build a PC in because you have to cram in all the PC components in limited space with limited expansion slots and drive bays.
As a result, building a PC in the small form factor case will be a hellish nightmare for first-time PC builders. A small form factor also relies on bespoke PC components because the standard-size PC components do not fit in this case, driving up the price of the build significantly.
On the point of limited space, this case size also suffers from a lack of customization options. What I mean by that is the slots for components are in fixed positions, so you cannot play around much to make the inside of the PC look neat and presentable. Talking about aesthetics, small form factor cases look the same, so you won’t get any style points from your friends if you show them this PC case.
Use Case
The small form factor case size is typically reserved for a special PC that is built with portability in mind. Such PCs include console-themed gaming PC, home theatre PC, Esports gaming PC, and other such use cases where a PC needs to be as portable as possible.
Mini Tower
Advantages of Mini-Tower
The mini tower case straddles a fine line between not being too small or too large. As a result, it is still manageable around smaller spaces and on small desks. This case achieves that size without connectivity and customization constraints of the short-form factor case.
The mini tower case can fit in the standard-size PC component. Since it is not bound by the bespoke component requirement of the small form factor case, the cost of building a PC with this case size is cheaper than a short form factor case.
Disadvantages of Mini Tower
Although the mini tower case solves most of the problems associated with a short-form factor case, it still has limited expansion slots. So, building an out high-end PC with a mini tower case will pose some challenges.
The mini tower PC case has less clearance for the graphics card. Therefore, premium GPUs with three fan heatsinks won’t fit into this case. Similarly, the space for the CPU cooler is also compromised, and a tall CPU cooler simply won’t fit.
Use Case
The mini tower case size is the quintessential option if space is a premium. Users with small desk space will find the mini tower case to be a good compromise between size and customizability.
Mid Tower
Advantages of a Mid Tower
The mid-tower case size is the most popular among all the different case sizes, and for good reason. It offers most of the customization options and retains almost the same number of expansion slots and drive bays found in the full tower case without being a nuisance to deal with.
The size of a mid-tower case, although not the smallest, is still pretty manageable, especially if the PC is going to fit on a desk for most of the while. All case manufacturers have a popular mid-tower case in their lineup, so there are plenty of options to choose from.
Disadvantages of Mid Tower
All things considered, the mid-tower case can be a bit too generic, especially for a seasoned PC builder. These cases are everywhere, and almost everyone is using them. So building a unique PC rig with the mid-tower case is not possible because chances are whatever idea you might have has been thought of before.
The sheer diversity of the mid-tower case makes it difficult to right the case for your needs. Even if you find the seemingly perfect case, chances are there will soon be a new option in the market which you will like more.
Use Case
The mid-tower case is the de facto choice for an amateur or a first-time PC builder. It offers the most convenient and hassle-free experience with plenty of expansion slots, drive bays, motherboard options, and other things to choose from. You simply cannot mess up building in a mid-tower case.
Full Tower
Advantages of a Full Tower
A full tower case, due to its massive size, provides endless options. It allows users to mix and match different You can get creative like the guys over at Origin and fit all the consoles into one full tower PC case as they have done with their Big 0 V3 gaming PC.
A full tower PC provides exceptional cooling potential. These cases can be used to great effect for both air cooling and water cooling. The extra space means full tower cases are equipped with tools for seamless PC cable management.
Disadvantages of a full tower
A full tower case is very difficult to manage due to its enormous size. Just unboxing a full tower case is a chore itself, so imagine how difficult it would be to move this thing when it is fully packed with PC components.
Another downside of a full tower case is that it can look incomplete. More often than not, if you don’t properly plan out the space utilization, there will be large pockets of empty space inside the case, which don’t look particularly appealing.
Which PC case size should you go for?
Perhaps the main question then remains which case is right for you? I wish there was a simple answer to this question, but as it stands, the choice of case size depends on a number of different factors. Let’s take a look at these factors in detail.
Space Availability
When selecting a case, the most important factor you have to consider is the space available on your desk. Remember, the case is not the only thing on your desk. You have to optimize the space for the other PC peripherals as well, such as the monitor, keyboard and mouse. For a small desk, my recommendation would be a mini tower case like the Lian Li Q58.
Portability
The idea of PCs being a desktop queen has drastically changed. With PC hardware getting increasingly powerful, the need for large PCs has diminished. A huge chunk of the population now wants a portable PC, and when it comes to portability, you cannot go wrong with a small form factor case.
Although a short form factor case is not the most user-friendly, you might need a professional’s help building a PC. However, once everything is said and done, you will have a small portable PC that you can use anywhere. If you fancy that aspect, look no further than the NZXT H1.
PC Specifications and Performance
As stated earlier, the case dictates which components and specs combination a PC will have. If you are hell-bent on building the best custom PC money can buy, then it wouldn’t be wise to start with a short form factor or a mini tower case because they limit options and restrict performance.
A full tower case specifically will be an ideal choice for an extremely high-end PC. The Lian Li 011 Dynamic XL does an excellent job at giving users all the space they want to fit large CPU coolers, E-ATX motherboard, multiple GPUs, a full-blown water cooling setup and more.
Cooling Capability
Cooling is perhaps an underlooked segment of a PC case, despite it being a very important factor to consider. Heat is the kryptonite of a PC, and continuous overheating can cause critical damage to the PC. It should be understood that larger cases provide more efficient cooling than smaller cases because more air flows through them. The best example of cooling is the Corsair 7000D because it is specifically optimized for airflow.
Budget
Some case sizes are more expensive than others. Generally, small form factor and full-tower cases command a premium over mini-tower and mid-tower cases. If you are on a limited budget and want a bang-for-buck PC case, then you cannot go wrong with a mid-tower case like the HZXT H5.
Conclusion
A PC case is not as simple as it may seem. It comes in four different sizes, and each size has multiple variations. It is even overwhelming for us to keep track of all the different sizes of cases that each manufacturer offers, so we can understand how difficult it must be for you.
Just remember, you cannot go wrong with a mid-tower case. If you are hesitant or confused as to which case size will suit your needs, opt for the mid-tower. It does almost all aspects pretty well and should be fine for the most part.
PC Case Size FAQS
What are the size differences in computer cases?
Computer cases come in various sizes, mainly categorized as Full Tower, Mid Tower, Mini Tower, and Small Form Factor (SFF). Full Tower cases are the largest, typically measuring over 20 inches in height, followed by Mid Tower cases at around 17-20 inches. Mini Tower cases are smaller, usually around 12-17 inches, while Small Form Factor cases are the most compact, often measuring less than 12 inches in height.
Does it matter what size PC case I get?
Yes, the size of the PC case matters based on the components you plan to use, the space you have available, the cooling and airflow requirements, and personal aesthetics. Make sure the case you choose can accommodate your motherboard, GPU, and other components, while also providing enough room for cable management and proper airflow.
How big should a PC case be?
The size of a PC case depends on your specific needs and preferences. For a high-performance gaming or workstation setup, a Mid Tower or Full Tower case is recommended, as they provide ample space for components and cooling solutions. If you want a compact system for everyday tasks, a Mini Tower or Small Form Factor case should suffice.
Does a bigger PC case mean better cooling?
A bigger PC case may offer better cooling potential due to more space for larger or additional fans and cooling solutions, such as air coolers or liquid cooling systems. However, cooling performance also depends on the overall case design, fan placement, and airflow patterns.
Can a full ATX motherboard fit in a mid-tower?
Yes, most mid-tower cases are designed to accommodate full ATX motherboards. However, it’s essential to check the case’s specifications to ensure compatibility before purchasing.
Is a bigger or smaller case better for airflow?
A bigger case can potentially provide better airflow due to more space for fans and less restrictive airflow paths. However, case design, fan placement, and the number of fans are crucial factors that contribute to good airflow. A well-designed smaller case can still offer adequate airflow for most components.
Do small cases have bad airflow?
Not necessarily. While small cases can be more challenging to optimize for airflow, many compact cases are designed with efficient cooling solutions and smart airflow management. The performance may not be on par with larger cases, but it can be sufficient for typical computing needs.
Do small PC cases overheat?
Small PC cases can potentially overheat if not adequately cooled. To avoid overheating in a small case, it’s essential to choose components with lower power consumption and heat output, invest in efficient cooling solutions, and ensure proper airflow and cable management.
Does fan size matter in a PC case?
Fan size does matter in a PC case. Larger fans can move more air at lower RPMs, resulting in better cooling performance and lower noise levels. However, the available space in the case and compatibility with other components must be taken into account when choosing fan sizes.