With all of the different mechanical keyboard sizes, it is difficult to find keycaps that will fit your keyboard. Some keyboards have smaller modifier keys, special right shift keys, weird spacebars, unique enter keys, and split backspace. The possibilities are endless. When looking for keycaps that will fit your mechanical keyboard, it is important to know what to look for.
You can check if a keycap set will fit your mechanical keyboard by checking the layout of your keyboard, knowing the size of special keys such as space, shift, backspace, enter, and the bottom row keys such as Ctrl, Alt, Win, and Fn. Some keyboards need extra keys or smaller keys than a standard layout.
We’ll go over all the details of what you need to look out for to make sure your next set of keycaps fits on your keyboard.
How Keycaps Are Measured: The Unit System
Before we start digging into the nitty gritty details, it’s important to define how keycaps are measured. When referring to keycap sizes, 1u is the size of one alphanumeric key. 2u is double the size of 1u, which would be two normal keys smushed together. The measurements get a little more confusing as they get bigger, such as 6.25u: which means the keycaps are the same length as 6 normal sized keys, plus an additional quarter of a key.
Is your Keyboard Standard Layout?
To check if a new set of keycaps will fit your keyboard, you should check if your keyboard is in the standard layout, or else you may run into some issues. When people refer to a standard layout, they mean the key sizes of the full-sized, tenkeyless, or 60% mechanical keyboard. When looking at this infographic from our Keyboard Size Guide, you can see how consistent the key sizes are for the 60%, full-size, and tenkeyless layouts.
When checking if your keyboard is standard layout, you mainly need to look at the bottom row key sizes. For the standard layout, the bottom row keys are typically 1.25u, and the spacebar is typically 6.25u. Before buying a keycap set, always double check the keycap sizes.
There are some full-sized mechanical keyboards by companies such as Razer, Logitech, and Corsair where the bottom row is referred to as “non-standard.” This means that it does not fit the sizes listed above and needs specially sized keycaps. Keyboard.University has a super easy to use printable keycap ruler that you can print out and then match your keycaps on top to see what size they are.
Some examples of mechanical keyboards with a standard layout include: Razer Huntsman TE, Ducky One 2 Mini, Anne Pro 2, Durgod Taurus K320 TKL, HyperX Alloy Origins Core, Keychron K8, Kemove Snowfox/Shadow, Drop CTRL, and more.
Standard Layout: Key Sizes
- Right Shift: 2.75u
- Enter Key: 2.25u
- Backspace: 2u
- Numberpad (zero, plus, enter): 2u
Non-Standard Layouts (Where Things Get Tricky)
Now that we’ve gone over the standard layouts, you’ll also realize that a LOT of mechanical keyboards out there are non-standard as well.
Below, we’ll try to be as comprehensive as possible, but when it comes to custom mechanical keyboards, there are many different layouts out there.
Full-Sized Non-Standard Layouts – Razer, Corsair, Logitech, Etc.
Many companies use non-standard bottom rows in their keyboard designs. The reason is unknown, but it makes finding fitting keycap sets and replacing the keycaps quite difficult.
Some people just replace the alphanumerics and leave the modifiers alone. If you look at the MaxKeyboards Keycap Compatibility and Size Chart, the bottom row of many Razer keyboards (not the Huntsman lineup) consist of 1.5u or 1u modifiers with a 6u spacebar. Corsair and Logitech have a similar layout, but they also include 1.25u modifiers in there as well and a 6.5u spacebar.
When buying pre built mechanical keyboards from these companies, be wary of the keycap sizes if you plan on replacing the keycaps in the future with different aesthetics.
With large keycap kits, it is possible to replace all of the keys. However, these kits are primarily available only in group buy or at a high price in the aftermarket. MaxKeyboards offers custom keycap layouts that you can design to match these sizes specifically.
Unique Keyboard Sizes: 65%, 75%, and 96%
Keyboards that have a more compact design such as 65%, 75%, or 96% layouts often have a smaller right shift to have room for the arrow cluster. These layouts are more unique and require different keycap sizes that differ from the standard layout. In addition, some of the keys will be on different rows, so the heights may be a little off if you are not using a uniform keycap profile.
Many times, this right shift is 1.75u rather than the full 2.75u of a standard layout. In specific keyboards such as the Ducky One 2 SF and the Womier K66, the right shift is 2u.
Keyboards in this category include Keychron K2, K4, and K6. It also includes mechanical keyboards such as the Drop ALT, Akko 3068, Magicforce 82, Vortexgear Race 3, Drevo Excalibur, iQuinix F96, Leopold FC660M, Leopold FC980M, and more.
Other keys to lookout for include the bottom right modifier keys. On some keyboards such as the Keychron K6, they are smaller to include room for the arrow cluster. Smaller mechanical keyboards tend to have more keys that allow you to change layers to access other functions. In this case, the K6 has a 1u Win, Fn1, and Fn2.
Is your Keyboard an Ergo Layout?
An ergonomic keyboard is great for those who want to type in a ergonomic and safe way for their bodies, but unfortunately, they do make buying a new set of keycaps quite difficult. Ergo layouts refer to mechanical keyboards that are split such as Alice-style layouts, the ErgoDox, Corne, X-Bows, and more.
These mechanical keyboards often have split spacebar modules on each side, which can hold different functions (space, shift, fn, etc) which means you’ll need to order keycaps with these unique sizes. When you’re looking for keycaps for these mechanical keyboards, there is often information on the size of each specific key because of the uniqueness of the design.
For example, ergo keyboards will often need 5 small stabilizers. The keycaps that go over those keys can vary. Oftentimes, with big group buy kits, you can pick an included ergo and spacebars kit to make sure that you have all of the keys you need.
An ergo mechanical keyboard that is semi-budget friendly, the Vulcan Maja, is an ergonomic 65% mechanical keyboard.
On the product page, you can see the sizes specifically stated for the hot-swappable PCB and the solderable PCB. Depending on the options you choose, there is the option to do a split backspace, split left spacebar, and more.
When buying keycaps for ergo mechanical keyboards, be sure to check the keycaps. Oftentimes, a full-sized keycap set with different sized shift keys will be able to make the fit. It might look strange putting a shift on a spacebar key, but it’ll at least cover the space available.
Unique Key Designs
When looking at the different key designs you may find that a split spacebar or backspace may be what you want to go with. We’ll talk about how to find a keycap set that works with one of these designs.
Split Spacebars
On many custom mechanical keyboards, you have the option to have a split spacebar or not. Having a split spacebar enables you to add keys that you press often such as Shift or FN to a space that is accessible by one of your thumbs.
Finding budget keycap sets for this is difficult. These keycaps are often available in only custom keycap sets sold during group buys, such as GMK, JTK, ePBT, etc.
These kits often enable you to pick and purchase an additional spacebars set. They also allow you to buy novelty keycaps, which often have a related symbol to the theme of the keycap set rather than a letter or number.
Split Backspace or Split Left Shift
Similar to split spacebars, sometimes custom mechanical keyboard PCBs allow you to split the backspace and then use the backslash key as backspace instead. This is useful for reaching backspace easier or to include delete into a compact keyboard that doesn’t have those keys.
A split left shift often fits ISO layout mechanical keyboards. For an in-depth explanation of ANSI vs ISO keyboard layouts, see this article we wrote here. When using left shift, your pinky finger may not need all of that space. In many languages, additional letters or symbols are needed and thus can be fit in that area.
These keycaps can be easier to find and fit than split spacebars. Many keycap sets come with ISO-compatible keys. For the split backspace, finding a 1.5u backspace may be difficult. However, changing the backspace to two 1u keys (probably delete and another key) is easy since those keys already come in a standard set.
Other Notable Layouts
For Mac keycaps, the possibilities are quite limited. KBDFans sells a PBT Mac Compatibility kit, and it offers the Option and Command keys in several different sizes. If you are looking for backlit Mac keycaps, there are two different options.
For different languages, make sure you have all of the keys that you need. We wrote about this in our user’s guide to keycap profiles.
Where to Buy Keycaps
There are many vendors where you can check for keycaps and purchase them. We use the following resources to keep track of mechanical keyboard and keycap group buys:
- Amazon (affiliate link)
- Drop (affiliate link)
- Mechanicalkeyboards.com (affiliate link)
- Mechgroupbuys – includes group buys to mechanical keyboards and keycap sets going on right now
- Keycaplendar – includes current and future group buys for keycap sets only
- Keycapsets.com – Basically a database of high-end keycap sets
For an in-depth list of resources on where to buy keycap sets, see our full in-depth article regarding that topic.
See additional reading materials that will help you with sizes and keycaps in general:
MaxKeyboards Keycap Compatibility and Size Chart
Keyboard.University Keycap Cheat Sheet