MINUTEMAN REVIEW may be compensated for purchases done through links on our site. To learn more about this, you can read through our Affiliate Disclaimer here.
The Glock series of firearms began in the early ‘80s and quickly took the world shooting community by storm. If you’re interested in buying a Glock pistol and this is one of your criteria, it’s worth finding out how many rounds each major variant holds.
Why Does Capacity Matter?
Glock semi-automatic pistols are known for having relatively high magazine capacities—the Glock 17 was one of the original wonder nine pistols. However, Glock manufactures magazines of varying designs and capacities to suit specialized uses.
When selecting a Glock for home defense, concealed carry, competition shooting, or hunting, it’s worth knowing how many rounds of ammunition its magazine holds. This can help you decide what pistol is most appropriate for your needs and how you should plan your loadout.
If you’ve ever asked, “How many bullets does a Glock hold?” this requires a brief explanation of terminology.
Glock Magazine Capacities
The bullet is simply the metal part that leaves the barrel. It isn’t alone, though. It’s loaded into a cartridge case, seated above a propellant powder charge, which is ignited by a primer. This complete package is called the cartridge or round.
Semi-automatic pistols are usually fed from detachable magazines. SAAMI defines a magazine as “[a] receptacle for a firearm that holds a plurality of cartridges or shells under spring pressure preparatory for feeding into the chamber.”
A magazine is distinct from a clip, which holds cartridges in proper sequence for loading into a magazine.
A magazine typically holds cartridges in one of two different layouts:
1. Single stack
In a single stack magazine, the cartridges are stacked one on top of the other in a single feeding column. This allows for a narrower magazine body and frame. Increasing the magazine capacity requires increasing the length.
2. Double stack
In a double stack magazine, the cartridges are stacked in a staggered or dual feeding column. This layout allows the magazine to remain shorter while holding more rounds by increasing the width.
The number of rounds a handgun should hold is a matter of debate. If you feel that you need more than a specific number, you should choose a weapon or a magazine that fulfills that requirement. Sometimes it’s necessary to strike a balance, however.
The standard Glock 17 magazine holds 17 rounds of 9mm ammunition, but this was a coincidence.
In subsequent pistol designs, this coincidence no longer holds true, which is why it’s necessary to know the magazine capacities of each Glock.
The Glock 19, introduced in 1988, is the subcompact variant of the Glock 17 — the full-size 9mm service pistol. Despite the designation, this pistol has a standard magazine capacity of 15 rounds, which is the equivalent of the contemporary Beretta 92FS (M9) and SIG P226.
Glock 20 and 40
The Glock 20 is a full-size handgun chambered in the 10mm Auto powerhouse. The G40 is the longslide variant. Both pistols are fed from a 15-round magazine.
The Glock 21, introduced in 1990, fires the .45 ACP cartridge. Before the G21’s introduction, most semi-automatic .45-caliber handguns were fed from single stack magazines holding fewer than 10 rounds of ammunition. The G21’s magazine holds 13 rounds standard.
In 1990, Glock introduced the G22 chambered in the newly developed .40 Smith & Wesson cartridge, beating the round’s co-designer to the market. The G22’s magazine holds 15 rounds but is also compatible with 16- and 22-round extended magazines are also available.
The compact variant of the Glock 22, the G23’s standard magazine holds 13 rounds of .40 S&W; however, 14-, 15-, 16-, and 22-round magazines are also compatible.
Glock’s first foray into the burgeoning concealed-carry pistol market, the firm introduced its first subcompact, the G26, in 1994. This semi-automatic 9mm pistol is fed from a flush-fit, double stack 10-round magazine.
The Glock 20, in 10mm, needed a subcompact variant of its own, so Glock unveiled the G29. This compact powerhouse has a magazine that holds, fittingly, 10 rounds of 10mm.
Chambered in .357 SIG, the G31 delivers ballistics equivalent to a .357 Magnum service revolver in a semi-automatic pistol. This round offers superior penetration and kinetic energy compared with defensive 9mm loads — and all from a 15-round magazine.
The G32 is the compact variant of the G31. This weapon is comparable to that of the G23 because the .357 SIG is derived from the .40 S&W. Its magazine holds 13 rounds, but 14-, 15-, and 16-round magazines are also available.
A subcompact Glock chambered in .45 ACP, the Glock 30 packs 10 rounds of .45-caliber firepower into its double-stack magazine.
Like the G30, the G36 is a subcompact Glock chambered in .45 ACP. However, the G36 is fed from a single-stack 6-round magazine, reducing its bulk.
Glock 42 and 43
Some shooters found that the Glock 26, despite its compact profile, was still wider than they would like. To remedy this, Glock designed the G43. A subcompact concealed carry pistol, the G43 is fed from a 6-round single-stack magazine, reducing the grip width by a one-fifth of an inch compared with the G26. The G42, chambered in .380 ACP, holds the same number of rounds.
The G43X is a single-stack subcompact 9mm pistol with a longer grip than the diminutive G43. As a result, it can accommodate a 10-round flush-fit magazine.
Despite the name, the G45 is chambered in 9mm, not .45 ACP (or GAP). The G45 is a compact variant of the G17 that doesn’t sacrifice magazine capacity. As a result, this pistol has the same 17-round magazine capacity as the pistol that started it all.
The G48, a slimline 9mm semi-automatic pistol, is fed from a 10-round magazine.
The G44, Glock’s compact rimfire pistol, is chambered in .22 Long Rifle. Its load-assist magazine holds 10 rounds. The G44 offers the centerfire shooter a low-cost training tool for familiarization firing and range practice. It’s also useful for teaching pistol marksmanship to new shooters.
Although not in sequence, there’s a reason for that. The Glock 18 is the selective-fire machine-pistol variant of the Glock 17. While not generally available to private citizens, the G18’s standard magazine is sold on the commercial market. The 33-round magazine extends well past the bottom of the pistol grip and is anything but concealable.
Spare Ammo & Mag Limits
When someone asks, “How many bullets does a Glock hold?” you can decide whether you need to carry or store additional loaded magazines in your home or vehicle. You may also want to carry spare magazines on your gun belt or in another convenient location.
While many Glock pistols carry an abundance of ammunition, you can never predict how many rounds you’ll need in a defensive shooting. It’s always worth being prepared.
Don’t forget that many Glock pistols are compatible with Glock magazines that fit larger Glocks. However, a larger Glock is almost never compatible with the magazines of a smaller Glock handgun.
If you live in a restricted state, you can usually find compliant magazines, regardless of which Glock model you have.
Glock pistols are available in a wide variety of magazine capacities, from six to 33. As a result, there’s a Glock pistol for every application.