The first question you ought to ask yourself before buying a shotgun is which gauge you’d like it to be. For most American shooters that choice comes down to 12 Gauge vs 20 Gauge.

There are a lot of variables to consider here. Different types of shotgun ammunition vary widely, as one shell may fire a single slug or over 2,000 shot pellets. But at its core, the winner of the 12 Gauge vs. 20 Gauge debate depends heavily on which you prefer: greater power, or more manageable recoil.

12 Gauge vs 20 Gauge

A 12 gauge shotgun load is heavier and delivers more power than 20 gauge ammo does. As a result, a 12 gauge is typically better equipped to take larger game. You do sacrifice some things for that power 12 gauge shotguns have more recoil than 20 gauge and the firearm itself is more of a burden to carry.

That’s the short answer and may be all you need. From here, we’ll get into the finer details of all the differences. To start the discussion let’s make sure you know what a shotgun gauge is.

What Is a Shotgun Gauge?

When you refer to a rifle’s or pistol’s caliber, you’re defining the internal diameter of its barrel. A 9mm pistol intuitively has a bore diameter of 9mm. Makes perfect sense, doesn’t it?

A shotgun’s gauge utilizes a far more archaic and inconvenient system. If you’ve ever bought fish hooks, you know that larger numbers actually correspond to smaller hooks. Shotgun gauges follow the same logic.

When you say a shotgun has an X gauge, you are saying its barrel would perfectly fit a lead ball weighing 1/X pounds. Thus a 12 Gauge shotgun would fit a 1/12 pound lead ball in its barrel; a 20 Gauge, a 1/20 pound ball. A 16 Gauge shotgun’s barrel would conveniently hold a one ounce lead ball.

If we applied caliber conventions to a shotgun, then a 12 Gauge would be .729 caliber and a 20 Gauge would be .615.

Note that the 410 Bore shotgun does not follow “gauge rules.” Its bore diameter is literally .410”, which would be equivalent to 67.5 Gauge. If a 410 Bore were actually a 410 Gauge, then its bore would share the approximate diameter of a .22 caliber pistol’s.

Popular Types of Shotguns

Here are the different gauges available on the market, in order of largest to the smallest caliber.

  • 10 Gauge – the largest and heaviest of the shotgun types. Not super popular due to its size, but it is popular amongst waterfowl hunters. 
  • 12 Gauge – perhaps the most popular shotgun on the market. Extremely versatile and functional for all endeavors ranging from hunting to target shooting.
  • 16 Gauge – a rare size to find anymore but a 16 is right in the middle of the road for size. Considered a jack-of-all-trades type of gun.
  • 20 Gauge – right behind the 12-gauge shotgun in popularity, the 20 gauge is very popular due to its manageable size compared to its effectiveness. A tremendous all-around gun for a variety of uses. 
  • 28 Gauge – this size is on the small end of the spectrum and primarily used by upland bird hunters due to its mobility and weight.
  • 410 Bore – the smallest shell on the market (that isn’t custom) is used for small game hunting and some self-defense. The shells used are small enough that some revolvers on the market can shoot them. 

12 Gauge vs. 20 Gauge: Velocity and Energy

12 gauge vs 20 gauge 20ga vs 12ga

A 12 Gauge shotshell has a significantly larger capacity than a 20 Gauge. Because it often holds a heavier slug or column of shot, however, the 12 Gauge shotshell’s larger charge of powder often produces a comparable muzzle velocity to the smaller 20 Gauge. But this is not always the case – 12 Gauge shotshells do tend to offer a faster average muzzle velocity.

Muzzle energy is simply a factor of muzzle velocity and projectile weight. Here’s where the 12 Gauge truly outclasses the 20 Gauge: Because the larger shell’s projectile(s) can be so much heavier, the 12 Gauge consistently packs a much heartier wallop than the 20 Gauge possibly could.

Take a look at this chart where we compare very similar shells by Winchester and Federal. The shells primarily differ in terms of their projectile weights – not their velocities – but that alone accounts for a staggering difference in how much energy either one can put out.

Total Projectile
Weight (gr)
Velocity (fps)
Combined Muzzle
Energy (ft lbs)
12 GaugeRifled Slug437.516002488
20 GaugeRifled Slug328.116001865
12 Gauge#4 Buckshot87511002351
20 Gauge#4 Buckshot492.211751509
12 Gauge#7.5 Shot437.512501518
20 Gauge#7.5 Shot382.812101244

If you’re hunting or defending your castle, the 12 Gauge almost invariably delivers superior stopping power. But his isn’t to suggest that the 20 Gauge is a weakling. Hunters and homeowners frequently put it to use just as effectively.

12 Gauge vs. 20 Gauge: Range and Spread

If the 12 Gauge’s greater size always meant it delivered a faster muzzle velocity, it would be easy to declare its range superior as well. In practice we see either shell capable of reaching the same distances as effectively as the other.

Yet the 12 Gauge has a trick up its sleeve. A typical 12 Gauge trapshooting shell holds 1 1/8 ounces of shot whereas a 20 Gauge holds 7/8 ounces. This extra 1/4 ounce of shot promotes a relatively denser spread at any range. To put it simply, as more shot exits the muzzle, more shot is going to make its way to the target. In a contest between analogous 12 Gauge and 20 Gauge shells, the 12 Gauge’s spread is always denser.

12 Gauge vs. 20 Gauge: Recoil

difference between 12 gauge and 20 gauge

How much recoil energy a shotshell generates is a matter of four factors: shot/slug weight, muzzle velocity, propellant weight, and shotgun weight.

For the sake of discussion let’s say all the 12 Gauge shells compared earlier have 18 grains of powder and are being fired from a 110 ounce Winchester SXP; the 20 Gauge shells have 15 grains of powder and are being fired from a 104 ounce Winchester SXP.

Finally, the 20 Gauge gets a leg up in this face-off! By sheer virtue of its lighter projectile(s), the smaller shell exerts significantly less recoil back against its shooter.

Energy (ft lbs)
12 GaugeRifled Slug28.79
20 GaugeRifled Slug17.56
12 Gauge#4 Buckshot51.1
20 Gauge#4 Buckshot20.83
12 Gauge#7.5 Shot18.71
20 Gauge#7.5 Shot14.13

Less recoil makes the 20 Gauge better in two important ways. First, there’s the obvious comfort factor. While the amount of kick you may actually perceive is subjective, the 20 Gauge’s objectively weaker recoil energy is bound to put less stress on your shoulder. Second, lesser recoil helps a shooter line up their follow-up shots more quickly. Whether you want to fire two shots in rapid succession while target shooting or dump a whole magazine into an advancing threat, a 20 Gauge will make the endeavor easier than a 12 Gauge could have.

What’s Cheaper – 12 vs. 20 Gauge?

Surprisingly enough, analogous 12 Gauge and 20 Gauge shotshells are comparably priced. You would expect a 12 Gauge shell which contains more lead, brass, plastic and propellant to cost more, but perhaps its greater popularity compensates for that disparity.

That said, you’re going to have access to more options when it comes to 12 Gauge ammo. This is its greater popularity at work again – manufacturers have more incentive to cater to the bigger audience.

The Takeaway

The 12 Gauge and the 20 Gauge are the most popular shotguns for good reason. Either will let you hunt deer and birds, play trap and skeet, and make a home invader wish he picked a different home.

While the 12 Gauge’s superior power may make it a more commanding solution for deer hunting, the 20 Gauge still outclasses the 223 Rem in terms of muzzle energy. You’re not putting yourself at a disadvantage if you select it for personal protection.

If you would rather have more power, a denser spread, and a greater selection of ammo to choose from, you’ll be better served by the 12 Gauge. If you would prefer a shotgun with less recoil for better comfort, easier follow-up shots, or to train a younger shooter, then the 20 Gauge is your shell.

Here are some of our top picks for each gauge: