Mechanical keyboards come in a confusing array of sizes with names like "65%" and "TKL." The number refers to how much of a traditional full-size layout the board keeps. Picking the right size is about balancing desk space, the keys you actually use, and your mouse comfort. Here is how the common layouts compare.

Full-size (100%) The classic layout with a number pad on the right. Choose it if you crunch numbers in spreadsheets or accounting software all day. The downside is width: the number pad pushes your mouse far to the right, which over time can strain your shoulder.

Tenkeyless (TKL, 80%) A full-size board with the number pad removed. You keep the function row, arrow keys, and navigation cluster (Home, End, Page Up/Down). For most people this is the easy, no-compromise choice: everything you regularly use, with your mouse much closer to your typing hands.

75% Takes everything on a TKL and squeezes it together, keeping the function row and arrows but stacking keys tightly. It is the most popular enthusiast size because it is compact yet loses almost nothing. Great for laptops users who want a familiar layout in less space.

65% Drops the function row but keeps dedicated arrow keys and a few navigation keys. To press F-keys you hold a function layer. This is a fantastic balance of tiny footprint and everyday usability, and a great first "small" board.

60% No function row, no arrow keys, no navigation cluster. Everything beyond letters and modifiers lives on a hidden layer accessed with a Fn key. It is wonderfully compact and frees enormous desk space, but there is a learning curve. Choose it only if you are comfortable using layers or you mostly type prose.

How to decide Ask yourself two questions. First, do you use the number pad daily? If yes, go full-size; if no, drop it. Second, how often do you use arrow keys and function keys directly? If constantly, stay at TKL or 75%; if rarely, a 65% or 60% will reclaim your desk without much pain.

There is no "best" size, only the best fit for your work. A common path is to start at TKL or 75% for a familiar transition, then go smaller once you discover how few keys you truly need. Because budget boards are inexpensive, many people end up owning two: a compact board for daily typing and a full-size for number-heavy tasks.