The Nomenclature of Handgun Sizes


The firearms industry and standardization are not good friends. For some reason, choosing one pattern for anything is often terrifying. It’s why we still have a dozen different optics cuts. One thing the industry has more or less standardized on is handgun sizes. We seem to have settled into a comfortable area for the various handgun sizes, so I figured I’d break it down for new shooters and give them an explanation of these more or less accepted sizes.

Digging Into Handgun Sizes

There are seven major handgun sizes that are more or less reserved for automatic handguns. Revolvers are a bit of their own world, of various sizes, for various purposes. We’ll cover automatics today and revolvers in another article. These sizes aren’t quite universal but are as close as we can get in the firearm industry.

Full Size

Full size is the duty-sized handgun variant. They are typically defined by a barrel length between 4 to 5 inches. These guns are typically around 5.5 inches tall and hold anywhere from 15 to 20+ rounds of ammunition when chambered in a caliber like 9mm. They tend to be doublestack firearms in the modern era. They are a popular choice for duty carry, competition, home defense, and concealed carry, with those who go a little hardcore with it.


Compact can be deceptive in its name. I’ll admit, it was the first time I saw a gun described as compact. I thought it was a bit of a bad description. Compact guns tend to have barrel lengths that are 3.7 to 4 inches or so. The height is about five inches max, and they also tend to have doublestack magazines. These guns are often considered the perfect jack-of-all-trades handgun size.

A new type of compact in the form of guns like the P365XL and the Hellcat Pro has introduced a thinner-than-average compact option as well. They are well suited for concealed carry, duty, and home defense.


Subcompact guns typically have a barrel length between 3.1 to 3.5 inches and tend to be 4.17 inches tall. These smaller firearms can come in both single-stack designs and doublestack designs. Most of the time, the subcompact handgun sizes are smaller versions of duty-sized and compact firearms like the Glock 26 and SIG P224.

Most companies also defined their single-stack 9mm handguns as subcompacts. Guns like the Walther PPS and Glock 43 tend to be thinner but roughly the same size in terms of length and height as their doublestack alternatives.

Micro Compact

Micro compact brings us a relatively new set of handgun sizes. These guns came about in 2018, and they were started by the premier of the SIG P365. A micro-compact tends to have a barrel length of about 3 inches and a height below 4.5 inches, depending on the magazine length. The defining feature of these firearms is their 1 to 1.1-inch wide grips with the ability to hold at least 10 rounds in a flush-fit magazine. These guns are typically reserved for concealed carry.

Competition / Long Slide / L

When we reach the bigger-than-duty size length, we start to see a mix of terms used to describe the guns. The two most popular are competition and long slide, with L often being the marker of a Long slide variant. These guns feature barrels that are typically 5.25 to 6 inches long, but they can be longer on occasion. This section of handgun sizes makes use of full-sized frames, so the height is still around 5.5 inches. These tend to be guns used for competition and hunting but are also somewhat common duty and home defense options.

X / Carry

Handgun sizes are always evolving, and one of the newer options is the X or Carry Models. Glock and SIG started the theme. Glock has the most famous model in the form of the Glock 19X, but SIG also has the P320 Carry, and the Arex Delta X is another X model. These guns combine a compact-sized slide and barrel length with a full-length grip module. They are popular for reasons unknown to me, but they tend to fill the same genre of firearms as compacts and are popular as jack-of-all-trades guns.

Pocket Pistol

The smallest of automatics are known as pocket pistols. These firearms are named because they very easily drop into your pocket. They often have single-stack magazines and feature a capacity of six to seven rounds. These guns have barrel lengths between 2.5 to 2.8 inches. They tend to be in calibers like .380 ACP and .22 LR, but .32 ACP and .25 ACP are not unheard of.

Handguns Sizes & You

In this online age, more and more people are shopping online. I often find that online descriptions are somewhat lacking. Some people may be looking for something that’s more akin to a micro compact and think the gun-size compact will fit their needs. Hopefully, this will give you a quick reference to handgun sizes and their uses.

Travis Pike
Travis Pike is a former Marine Machine gunner who served with 2nd Bn 2nd Marines for 5 years. He deployed in 2009 to Afghanistan and again in 2011 with the 22nd MEU(SOC) during a record setting 11 months at sea. He’s trained with the Romanian Army, the Spanish Marines, the Emirate Marines and the Afghan National Army. He serves as an NRA certified pistol instructor and teaches concealed carry classes.