What does MOA mean and how do I apply it?

I think we can agree that if you’ve ever done any research on shooting better, you’ve run into something called minutes of angle

…and it can be about as clear as mud.  

Or is it?

Well, it turns out that you can start shooting like a trained Army marksman right now and never be confused about Minutes of Angle again…

…by doing one simple formula.

In this post, we’re going to show you what that formula is, explain Minutes of Angle from the ground up, and show you how you can confidently use minutes of angle and consistently hit your target each and every time.

Why is MOA Important?

When looking at a scope, you may read that it has 1/4 MOA adjustments.

Or, a rifle may claim to shoot “sub MOA”. 

You might be wondering: “Well WTF does that mean and can’t I just put the crosshairs on a target and pull the trigger!?”

Here’s the deal:

No, you can’t- not if you want to hit the target consistently.

Now: before we dive into what minutes of angle are all about, let’s first discuss why we use them in the first place. 

The main word that we want to cement in your head is “compensation.”

The minute of angle is a measurement that helps a scope…

…compensate for the drop of your bullet as it leaves the barrel and/or how the wind moves it.

That’s it- plain and simple.

The rest of what we’re talking about is getting into the nuts and bolts of how to calculate minutes of angle.

The Basics of Minutes

Minute of Angle (known as Minute of Arc in mathematical terms) is also known as MOA in reference to marksmanship. 

Ironically enough, it has nothing to do with a minute of time that has elapsed. 

One minute of angle is an angular measurement that is 1/60th of a degree… 

…and it’s called a “minute” because we’re referring to the 60 degrees in the measurement.

A compass has four directions (north/east/south/west) and 360 degrees.

There is 60 MOA in between each degree.

One minute of angle is equal to about 1 inch of spread at 100 yards (technically 1.047 at 100, but 1 inch is easier to keep in your head.)

A simple 1:100 ratio:

100 yards    = 1-inch spread

200 yards    = 2-inch spread

300 yards    = 3-inch spread

1,000 yards = 10-inch spread

Now:

Let’s use the analogy of a flashlight to illustrate what I’m talking about.

Imagine that you’re using a flashlight that casts light in a very tight circle. 

If that flashlight cast its light at 1 MOA, then at 100 yards the light would only illuminate a 1-inch circle.  

As the light goes beyond 100 yards, the circle gets bigger.

At 200 yards it would illuminate a 2-inch circle, 300 yards a 3-inch circle, and finally at 1000 yards, a 10-inch circle.

Simple enough right?

Here’s a spreadsheet to show what we mean: 

MOA Estimated Inches of Spread Exact Inches of Spread at 100 yards
1 1 1.047
2 2 2.094
3 3 3.141
4 4 4.188
5 5 5.235
6 6 6.282
7 7 7.329
8 8 8.376
9 9 9.423
10 10 10.47

Want to know the best part?

You don’t need to know the exact inches of spread because… 

…using our formula, you’re going to achieve the same accuracy.

And you can do the calculations in your head MUCH quicker using the estimated inches.

However, some people enjoy being difficult.

If you, or someone you know, enjoy being difficult, by all means, use the exact inches of spread, but we’d recommend using the estimated inches of spread. 

You might be wondering: “Okay Bobby great, but how is that useful?”

Don’t worry!

We’ll show an example of how this works, but before we do…

…we need to think about the scope itself and how it plays its part. 

Scope Basics and Minutes of Angle

Every scope has a dial on top that twists and makes clicking noises. 

When you twist the dial on the scope, the dial actually moves the crosshairs (also known as a reticle for the fancy folks) either up and down, or side to side. 

These twists and “clicks” are what allow you to actually compensate for MOA by adjusting the angle that the crosshairs are facing…

…so when we say ‘one click left and two clicks up,’ we’re actually referring to adjusting the dial on the scope to make those adjustments.

“Well Bobby, that’s great and all but how do these clicks on the scope come into play?”

Good question!

Now… every scope also adjusts for MOA in different increments.

Depending on the scope, the clicks are typically translated into the following amounts of MOA:

1 Click = 1/2 MOA

1 Click = 1/4 MOA

1 Click = 1/8 MOA

Now STOP STOP STOP! Don’t get ahead of yourself with trying to do any calculations. 

I assure you the calculations are really simple…

…but let’s take it one step at a time so there’s zero confusion. 

Distance

The next building block we want to introduce into the equation is distance. 

The distance that you’re shooting from is what determines how many clicks the scope will need to be moved in order to compensate for bullet drop. 

Think about it like this:

A short shot won’t require as much angle as a long shot because there’s less distance for the bullet to drop. 

Here’s a simple illustration:

Imagine the throwing path of a 5-yard pass and a 50-yard pass with a football.

With the 5 yard pass, you can basically gun it to the receiver and the ball will travel in a straight line.

No compensation required! 

But what about the 50-yard pass?

Are you going to be able to gun it to the receiver in a straight line?

Unless you’re a roided up Cam Newton, the answer is probably no. 

For the long pass, you’re going to give the ball a higher angle in order to reach the receiver.

This is the same concept with minutes of angle. 

Our Easy MOA Formulas

Now:

Here’s an example of the two concepts we just discussed, i.e. minutes of angle and using your scope.

Let’s say you have a scope that compensates for MOA in 1/4 MOA per click, and we already have our scope zeroed at 100 yards. 

In simple terms, a zeroed rifle means that if you take a shot at 100 yards, your bullet will hit exactly where the crosshairs are located.

Now, let’s say we want to shoot something at 200 yards.

What do we do? 

We know from our discussion above that, because of bullet drop, if we place the crosshairs directly on the target, we won’t hit the target exactly where we want.

So… 

We must compensate for this drop by using minutes of angle.  

For the sake of illustration, we’re going to take a shot at the new target with no adjustments. 

Now:

We put the crosshairs on the target, fire and notice that our shot is 4” below the target.

This means that we have 4 inches of adjustment to make up.

Keep this in mind for our simple conversions below. 

To quickly figure out how to make up for this adjustment, here are some simple conversions you can do in your head. 

Remember:

The whole point of these conversions is to convert the inches of adjustment into clicks on the scope.

So, from a high-level view, the formula and conversions go as follows:

Find distance > Convert to Inches of Spread > Know Your Inches of Adjustment > Convert to Clicks   

Here are the actual conversions that will hopefully illustrate what we’re talking about:

Distance → Inches of Spread 

Inches of Adjustment Inches of Spread → MOA Adjustment

MOA AdjustmentScope MOA Increments → Clicks

Now, where it can get confusing, is the constant reference to inches. 

One is an inch of spread and another is inches of adjustment, so… 

…be sure not to conflate the two into the same measurements. 

The spread is referring to the spread that we used in our flashlight analogy above.

The inches of adjustment is the distance gap that we need to make up to hit our target. 

Most first shots at a new distance will have a new inches of adjustment because the bullet will tend not to hit the target on the first shot.

This is why the clicks on a scope are measured in fractions of MOA.

So back to our example: 

  • A 200-yard shot, 
  • With 4 Inches of adjustment and,
  • A scope that adjusts in 1/4 MOA increments.

200 Yards → 2 inches of Spread

4” Inches of Adjustment2 inches of spread → 2 MOA Adjustment

2 MOA Adjustment1/4 MOA increments → +8 Clicks

So in summary, +8 clicks on the scope will compensate for the 4 inches of adjustment at 200 yards. 

Remember dividing fractions in high school?

Didn’t think so.

You were probably too busy making amateurish attempts at sexting Becky in the front row.  

Math Tip:

Instead of dividing, flip the fraction and multiply.

You get the same result and it’s way easier.

So in terms of 1/4, it’d look like this in your head: 

3 * 4 → 12 clicks

So, if the scope increments were in terms of 1/8 we’d multiply the 3 MOA by 8.

It would look like this: 

3 * 8 → 24 Clicks

Simple math. 

Let’s do one more example to illustrate. 

Let’s say after hitting our 200-yard shot, we want to take a 600-yard shot.

What do we do? 

Well, we don’t know how many inches of adjustment we’re going to need…

…so we take a shot to determine the inches of adjustment we need to make up. 

We take a shot and we have 24 Inches of Adjustment to make up.

We now have all the ingredients we need to do our equation

  • A 600-yard shot, 
  • With 24 Inches of adjustment and,
  • A scope that adjusts in 1/4 MOA increments.

Reminder: 

Distance → Inches of Spread 

Inches of Adjustment Inches of Spread → MOA Adjustment

MOA AdjustmentScope MOA Increments → Clicks

So let’s fill in the equation to determine our clicks. 

600 Yards → 6 Inches of Spread

24 Inches of Adjustment6 Inches of Spread → 4 MOA Adjustment

4 MOA Adjustment 1/4 MOA Increments → +16 Clicks

So, 16 Clicks on the scope will compensate for the 24 Inches of adjustment at 600 yards.

Very simple math. 

Easy right?

You might be wondering: “Wait wait wait!!! Why is there a positive sign next to the clicks?” 

Good question!

Think about clicks in terms of a simple number line with positive and negative numbers.

-3 -2 -1 0 +1 +2 +3

Remember:

We’re zeroed at 100 yards, so that is our “0” in our number line.

In the real world, sometimes targets are closer than100 yards…

In that case, we’d have to move to the left of zero on the number line (into the negative numbers) in order to compensate. 

In practice, it just means moving the dial with clicks in the negative direction as opposed to a positive direction.

Now:

If you’ve followed us so far the next calculation will be easy. 

After we just took (and nailed) our last two shots, let’s say our next target is now at 25 yards.

What do we do?

We take a test shot to determine our inches of spread and then we do our simple calculation.

In this case, we take a shot and have 1 inch of adjustment.

Remember our high-level formula below to help you out:

Find distance > Convert to Inches of Spread > Know Your Inches of Adjustment > Convert to Clicks   

Our ingredients: 

  • A 100-yard shot, 
  • With 1 Inch of adjustment and,
  • A scope that adjusts in 1/4 MOA increments.

25 yards → -0.25 inches of spread

1 inch of adjustment-0.25 inches of spread → -4 MOA Adjustment

-4 MOA Adjustment1/4 MOA Increments → -16 clicks

So in this example, we’d have to adjust the scope -16 clicks in order to compensate for the distance. 

Want to know the best part?

You can do this same simple calculation for any distance and nail your target. 

Simple right?

To reiterate, the scope in this example would be described as shooting 1/4 MOA or 1/4 minutes.

Now here’s some homework for you:

With these ingredients, how many clicks would you need in order to hit your target?

Distance: 500 Yards

Adjustment: 10 Inches

Scope: 1/4 MOA

Clicks = ????

Think you have the answer?

Put your answer in the comment box and we’ll let you know if you got it.

Now:

Let us now think about MOA for the rifle. 

Every rifle has its own MOA (you may also hear it also just called minutes,) which essentially means you could strap that rifle in a vice, shoot five rounds through it…

…and it will hit the target in a spread of inches according to its MOA. 

For a rifle that has a 2 MOA, the conversions are very simple:

Yardage * MOA = Inch spread

100 yards * 2 MOA → 2-inch spread of each other

500 yards * 2 MOA → 10-inch spread of each other

1000 yards * 2 MOA → 20-inch spread of each other

The reason why this is important is because we need to know the limitations of the rifle that we are using. 

Understanding the capabilities of the rifle will help you understand your maximum effective range. 

Here’s the kicker:

If you had a rifle that only shot a 3 MOA, and put that rifle in the hands of a very experienced long-range shooter…

…that expert shooter could still only shoot to the 3 MOA limitations of the rifle.

Here’s an example:

Let’s think about deer lungs as a target. 

Deer lungs are about 6 inches in diameter, so we would want to be able to shoot within a 6-inch spread so we don’t miss the lungs. 

Do you follow me, so far?

Now, let’s say we’re using a rifle that only shoots 3 MOA. How do we know what our effective range is?

Remember our ingredients:

Inches spread (deer lungs) = 6 inches

Rifle MOA Capabilities        = 3 MOA

Effective Range                   = ??????

Simple, we refer to our handy formula:

Effective Range * MOA = Inch spread

Or another way to look at it:

Inch spread MOA = Effective Range

So…

6 inch spread / 3 MOA = 200 Yard Effective Range

In this case, the rifle would only be effective for deer at 200 yards (because that would be a 6-inch group.)

Now, as a contrast, let’s say you have a rifle capable of shooting a 1/2 MOA. 

What would be the effective range for that same deer with a 6-inch spread?

We refer to our last formula:

Inch spread MOA = Effective Range

6 inch spread1/2 MOA = 1200 Yard Effective Range

In this case, the effective range of the rifle is 1200 yards.

Make sense?

Dope Card

I personally carry a “dope card” (the scope equivalent of a cheat sheet) on my rifle which tells me the MOA adjustments for my scope at every distance. 

Want to know the best part?

I determined the adjustments by doing the exact process I outlined above for you at every distance by marking the clicks on my dope card…

…and now I don’t have to do a readjustment every time I take a shot. 

Now: I shouldn’t even be talking about this yet but…

…this becomes very important when compensating for range and wind. 

For example, if you had a rifle scope that had “positive tracking” (that is a whole other story in itself) and wanted to take a long-range shot…

…if you knew the range and the wind, you could add the MOA adjustments into your scope so that you could hold on target and make the shot. 

Shooting with the wind is another story for another time (be patient young grasshopper,) but it starts with understanding MOA.

Final Thoughts on MOA

Although MOA is a standard unit of measurement among most shooters, some gun nerds are going to use MILS (short for Milliradian, which is 1/1000th of a radian.  

This is the same concept as MOA, but it is a courser unit of measurement (at 100 yards a MIL is 3.6 inches) and less commonly used.  

My advice?

Focus on learning MOA and leave MILS for the gun nerds who have to be different from everyone else.