What Is MOA In Shooting: Minute Of Angle Explained

Written By John VanDerLaan 

Updated

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Whether it's on your rifle or your scope, you've likely seen MOA written somewhere, an acronym for "Minute of Angle," an important unit of measurement for shooting. Unfortunately, there is a lot of misconception in the hunting community about MOA, and many do not even understand what it is or how important it is for accurate shooting on the hunt.

Let's clear things up.

What Is MOA?

What Is Moa

MOA, or "minute of angle," is a unit for measuring part of a circle. Basically, it's 1/60 of one degree. There are 360 degrees in a circle, so there are 21,600 minutes in a circle.

For shooting, think of yourself as the center of the circle and the target as sitting on the edge of the circle. You could divide this circle you've imagined into 360 pie slices of equal size. You could further divide each of those slices into 60. The edges of these slices are "one minute," which is obviously going to be pretty small. After all, it's 1/21,600 of the whole circle.

Now, in a mathematical sense, the MOA depends on the circle's radius, in this case, how far you are from the target. With this measurement, you can theoretically do the math to figure out how long the MOA is using pi and all those formulae you learned in 9th grade. But let's keep it simple.

For shooting purposes, the MOA is calculated based on a target at 100 yards, a round number that makes things easy. 100 yards equates to 3,600 inches. To get the circumference of the circle around you, multiply by two and then by pi, which gets you 22,620 inches. Divide by 21,600 like we said, and you get an MOA of 1.047 which is small enough to round to one inch.   

What Does MOA Mean?

MOA means "minute of angle" and, most basically, refers to the distance between two things on the edge of a circle. In shooting, it refers to the distance between a shot with a projectile weapon and something else. It could be the distance between two or more shots or the distance between the shot and the bullseye.

The shooter, in this case, is at the center of a circle, and the target lies on its edge. Above, we did the math to determine the MOA at 100 yards, which is the standard, and got one inch.

In other words, if you're shooting at a target at 100 yards, and two bullets land one inch apart, they landed one MOA apart, plain and simple. This is important, though, because if the target is farther away, the bullets will land farther apart, and if the target is closer, they'll land closer together. Nevertheless, the difference between the two shots is one MOA, giving you a standard with which to judge the rifle's accuracy. 

How Do You Use MOA While Shooting?

View Of Target Through Scope

MOA is the unit of measurement you have to use when tuning your rifle for accuracy. Accuracy is based on angles, so you can't measure simple distance. For example, if your shot lands one inch off, you can't just adjust your scope one inch. It all scales with distance. A small difference at short range will magnify to a huge difference at far range.

As a result, most scopes have settings for MOA. If your shot lands one MOA to the left, then adjust your scope one MOA to the left. It's that simple.

You can also use MOA to gauge a rifle's accuracy in general. A rifle that consistently shoots groupings of bullets all within one MOA of each other at 100 yards is more accurate than one that shoots groupings spread out over several inches. In fact, many rifles come with an MOA rating that reflects how accurate the rifle is, all else being equal.

MOA vs Distance

Target With Holes From Sighting In Rifle With Scope

If you're using MOA to adjust your scope, just remember that it's not the same as distance. Yes, if you're shooting at 100 yards, then one inch equates to one MOA. If your bullet lands one inch to the left of the bullseye, adjust your scope one MOA to the left.

However, if you're shooting a target at a different distance, you'll have to do some basic math. For instance, if the target is 200 yards away, then one MOA is two inches. So if your bullet lands one inch to the left, you only need to adjust your scope half an MOA to the left. If you're shooting a target 50 yards away, then one MOA is half an inch. So if your bullet lands one inch to the left, you need to adjust your scope a full two MOAs to the left.

MOA vs MIL

MIL means milliradian and is just a different unit of measurement for measuring the same thing: the distance along a circle's circumference, i.e., an angle. It's like pounds and kilograms. Both measure the same thing: weight. They're just different units.

At 100 yards, one MIL equates to 3.6 inches, which is not a very convenient number. However, at 100 meters, one MIL equates to 10 centimeters, which is indeed quite convenient if you're familiar with the metric system. MIL scopes then usually have adjustment units of 0.1 MIL, which equals one centimeter on the target at 100 meters. Simple, round numbers.

Since most people who aren't engineers or physicists are more familiar with degrees than radians, MOA might seem more intuitive. On the other hand, MIL is widely used in military and law enforcement, so many people already have practice with this measurement.

At the end of the day, it depends on personal preference and your scope. Certain scopes come with MOA adjustments and others MIL. Some come with both, allowing you to choose which you prefer. 

MOA And Scope Quality

High End Stealth Vision Rifle Scope

These days, if you're shooting a relatively new, modern rifle, MOA is more important when considering your scope than the rifle itself. A correctly sighted-in scope will let you take advantage of the rifle's inherent accuracy, which can get down to 1/4 MOA on high-end rifles.

A high-quality scope allows you to make fine-tuned adjustments with small MOA, ¼ MOA or less. This means you can get as precise as possible, correcting even small distances from the bullseye that would, of course, magnify at longer range. After all, this means you can correct your aim even if your shot is off by just a quarter inch at 100 yards.

Additionally, a high-quality scope should maintain those adjustments and make them consistently. If a click of the adjustment knob equates to 1/4 MOA, then it should adjust the angle exactly that amount every time. And it shouldn't wiggle, causing the scope to come off by even 1/10 MOA.

Different MOA Scope Turrets

2 Different Scope Turrets With Same MOA

When you're looking for a scope, you'll probably notice they come with different kinds of MOA turrets. Some have big, easy-to-grab turrets that make it easy to adjust the scope, especially in high-stress situations or bad weather. These are nice for hunting situations, of course. 

Others might have low-profile turrets that are sleek but require a tool to adjust. These tend to be sturdier, more precise and more consistent… but more of a hassle. You might want one of these for hunting if you hunt over long distances, but otherwise, they're primarily for target shooting.

The kind of turret you choose can impact how quickly and accurately you make MOA adjustments. Big turrets are awesome for quick, on-the-fly changes. But if you're going for a low-profile hunting setup, you might prefer something more discreet, even if it's a bit harder to adjust. The key is to match the turret to your specific shooting needs.

How To Calculate MOA Adjustments With Examples

1 Click = 0.25MOA Written On Scope

You don't need an advanced degree in physics to calculate MOA, but you do need some elementary-level math. Just remember that one MOA is one inch if you're shooting at a target 100 yards away. From that, you can easily calculate one MOA based on other target distances.

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Let's take a look at some examples.

MOA at 50 Yards

Maybe you don't have much room in your backyard and can only sight in your scope at 50 yards. No problem. 50 yards is half of 100, so just divide the one MOA measurement by half as well. One MOA is half an inch. 

Therefore, if your shot is off the mark to the left by one inch, that's the same as two MOA. If your scope has adjustments for 0.25 MOA, then you have to turn it eight clicks to the left.

Skeptical? Let's check the math.

50 yards are 1,800 inches. Multiple by two and then by pi. This gets us 11,310 inches for the circumference of our shooting circle. Divide by 21,600 for an MOA of 0.52 inches. Close enough to half an inch for all practical purposes.

MOA at 200 Yards

Trajectory Difference Between 100 and 200 Yards

Image Credit Hornady.com

As we just saw, the MOA measurement scales pretty easily. 200 yards is double 100 yards, so we just double the MOA to two inches. If your shot is off one inch at this distance, you only need to adjust half an MOA, two turns of the scope turret if it has clicks at 0.25 MOA.

Again, we can check the math. 200 yards are 7,200 inches. Multiple by two and pi for 45,216, then divide by 21,600 for an MOA of 2.09, which rounds to two inches.

MOA at 70 Yards

Okay, we wanted to give you a more complicated one so you can get a feel for the formula. After all, you may not have a target set at a conveniently round distance like 50 or 100 yards. 

Here we can use the example of 70 yards. 50 yards is half of 100, but what is 70? Well, it's 7/10 of 100, 70 percent, 0.7, however you want to write it. Therefore, one MOA at 70 yards is 0.7 inches. If your shot is off by one inch, one divided by 0.7 is 1.43, close to 1.5 MOA. If your scope has clicks for 0.25 MOA, you can adjust it six clicks and try again.

This is a simple formula and works for literally any number, though we recommend using target distances with as round of numbers as possible to make your adjustments more precise. For instance, if your target is 127 yards away, then one MOA is 1.27 inches. Get it?

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FAQs

What is minute of angle used for?

Minute of angle, or MOA, is used to judge the accuracy of a projectile weapon, normally a rifle, or its scope. MOA refers to the angular distance along the circumference of the circle around a shooter at its center, equating to 1/60 of one degree. At 100 yards, this equals one inch.

Therefore, you can use MOA to describe how accurate a given rifle is. For example, you may see a precision rifle described as "sub-MOA." This means that it's capable of firing a group of shots all within one MOA of each other, or within one inch of each other at 100 yards. 

These days, high-end rifles commonly shoot at ¼ MOA or less, meaning that all else being equal, bullets from these rifles land within a quarter inch of each other at 100 yards, often less than the diameter of the bullet itself depending on the caliber. When shooting a rifle with this much precision, your technique as a shooter and the accuracy of your scope are much bigger factors when it comes to accuracy than the rifle's MOA.

Additionally, you use MOA to sight in your scope. Center the scope on the bullseye and take a shot. Then measure how far off if it is. Assuming the target is 100 yards away, if the bullet landed one inch off the bullseye, then you need to adjust your scope one MOA. 

What is 1.0 MOA?

Technically, 1.0 MOA is 1/60 of one degree of a circle. A circle has 360 degrees, so 1.0 MOA is 1/21,600 of the circumference of a circle. 

Exactly how long this is depends on the size of the circle. If your circle is one yard in diameter, then one MOA is a tiny 1/10 of a millimeter. On the other hand, if your circle is a mile in diameter, an MOA is a full nine inches.

To make things easier, we calculate 1.0 MOA at 100 yards for shooting purposes. This makes 1.0 MOA one inch, which is a simple number for adjustments.

What is better 1 MOA or 2 MOA?

If you are looking at rifles, one rated with an accuracy of 1 MOA is "better" than one rated at 2 MOA, at least as far as their accuracy is concerned. 1 MOA in this case means that the machining of the rifle is precise enough to produce a grouping of shots all within 1 MOA of each other, or all within one inch of each other at 100 yards. Two MOA means that the shots all land within 2 MOA of each other, or all within two inches of each other at 100 yards, much less accurate.

If you're curious, we can see how severe this difference is at longer ranges. At 500 yards, the 1-MOA rifle is going to group shots within five inches of each other and the 2-MOA rifle within 10 inches of each other, definitely enough to miss a buck's kill zone. 

Meanwhile, a precision rifle shooting at ¼ MOA will still group bullets within 1.25 inches of each other at 500 yards. As you can see, a lower MOA is better, especially if you're going to be hunting at longer ranges or hunting smaller game. 

What MOA is best for a rifle?

Simply put, the lower MOA the better, but a better question might be how "good" of an MOA do you really need? Rifles with super low MOAs, we're talking around ¼ MOA or even lower, cost a lot of money and are likely overkill unless you are hunting over incredibly long ranges.

Most hunting is done around 100 yards, so we can consider an MOA to be an inch for hunting purposes. In other words, a 1.0-MOA rifle is going to shoot its rounds all within an inch of each other as long as you're doing your part. That's plenty accurate for big-game hunting. 

We'd consider 1.5 MOA to be the upper limit for most hunting purposes with sub-MOA to be more than enough. 

What is an acceptable MOA for a rifle?

Again, this depends on your purposes, but for usual whitetail deer hunting, 1.5 MOA is acceptable with 1.0 MOA being a bit more ideal. Sub-MOA is more than enough, but you might consider it if you're an expert hunter hunting over longer distances or if you're hunting smaller game and need to be more precise.

What is a good group at 100 yards?

When shooters talk about a "good group," they mean how close together their shots land on a target. At 100 yards, many consider a good group to be shots within a one-inch circle, which aligns with a 1.0-MOA rating since one MOA is one inch at 100 yards. In this case, your rifle is pretty accurate.

However, "good" can be subjective and depends on your goals. If you're a hunter, for example, a 1.5 to two-inch group might be perfectly acceptable, as it's more than accurate enough for most game. Consider that the kill zone on a small whitetail deer is already over eight inches wide, with those of big bucks reaching as much as a foot.

For competitive shooters aiming for high precision, though, even a one-inch group might not cut it, so you'd aim for sub-MOA groupings. A high-end rifle shooting at ¼ MOA may be needed to achieve a "good group" in this case.

How many inches is a MOA?

One MOA is not an exact number of inches since it is a measurement of angle, but for shooting purposes, you generally see MOA calculated at 100 yards, in which case it equates to one inch. However, if the target is farther away, one MOA will be larger, whereas if it's closer, one MOA will be shorter.

The full math is above, but just know that this number scales easily. One MOA is one inch at 100 yards, two inches at 200 yards, three inches at 300 yards, etc.

If your scope adjusts 1/4 MOA per click, how many clicks are needed to move 2 inches at 100 yards?

In this case, you need to adjust the scope by eight clicks. First, remember that at 100 yards, one MOA is one inch. So if you need to move the bullet two inches, that means two MOA. If your scope adjusts at ¼ MOA per click, that's four clicks per MOA, or eight clicks for two MOA. Easy, right?

Just remember to adjust your scope the right way. If your shot was off by two inches to the left at 100 yards and your scope adjusts ¼ MOA per click, that means you should turn it eight clicks to the left.

Final Thoughts

If you're a hunter, MOA isn't just some technical number written on the side of your rifle's box. It's an important factor in your hunting success. Not only does it reflect the accuracy of a given rifle, but it's also the measurement you need to use to adjust your scope. By understanding what an MOA is and how it translates to scope adjustments, you can sight in your rifle more accurately and be sure that your shot hits the killzone time after time.

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John VanDerLaan

John VanDerLaan is the managing editor here at DeerHuntingGuide.net. He oversees a team of editors, writers and pro staff that are subject matter experts in hunting and hunting gear. John's expertise includes thoroughly testing all types of hunting gear, as well as hunting all over the U.S. and Canada. While his hunting expertise includes game birds, small game and large game, his favorite game animal is the whitetail deer and he loves to share the knowledge that he has gained over 40 years of chasing the wily whitetail with both archery gear and firearms. John is an active member of the Outdoor Writers Association of America.

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