What are Mils? Understanding and Using Milliradians

by Ryan Cleckner

November 20, 2021

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If you’re looking to understand what Milliradians (Mils) are and how they’re used in shooting a scoped rifle, you’re in luck!

In this Milliradian guide, we’re going to teach you everything from the meaning of “Mil” to how to use Mils.

If you’re here to learn about Mils, there’s a good chance it’s because you’re interested in learning how to adjust your rifle scope or zero (sight in) your rifle. If so, you should also check out those articles next.

Also, if you’re curious about Minutes of Angle (MOA), which are very similar to Mils, you should check out our article on Understanding MOA.

What are Mils?

Before we get into some trigonometry about how Mils work (I’ll try to keep it simple and even tell you which parts you can skip if you like), let’s first break down what the term “Mil” stands for and breakdown the definition of “Milliradian.”

Mil Definition: “Mil” is an abbreviation of Milliradian. It does NOT stand for “military.”

Let’s break down the term “Milliradian.”

The prefix “Milli” comes from the metric system and it means 1/1000th.

For example, one millimeter is 1/1000th of a meter and one milliliter is 1/1000th of a liter.

So, we know that one milliradian is 1/1000th of a radian.

But what the heck is a radian?

I’m glad you asked…

A radian is a trigonometry term for a certain angle of a circle based on the radius of that circle.

For a very rough estimate of how big of an angle 1 radian is, picture a pie cut into 6 pieces. One of those pieces is roughly one radian (it’s just over 57 degrees).

I wrote above that I’d let you know what part to skip if your eyes will cross with trigonometry talk… if this applies to you, you can start skipping now. 🙂

[SKIP START]

More precisely, there are 2π radians in a circle. 2*3.14 = 6.28 radians in a circle.

A radian is determined by the resulting angle between both ends of a radius length section of the circumference of a circle.

Mil Diagram
Mil Diagram

Wait. What?

Let’s use this diagram for some help.

If you take the radius, which is the measurement from the center of a circle to its edge (A in the diagram), and “wrap” it around the outer edge of the circle (B), then the angle from the center of the circle to both ends of (B) is one radian (C).

Hopefully, you can see the rough estimation above gives you a good enough idea: it’s about 1/6th of a pie or about 57 degrees. 🙂

If you like math and you’d like to learn more about radians, check this out.

[SKIP END]

Ok. We know what a radian is and we know that the prefix “milli” means 1/1000th. Therefore, we now know that a milliradian is an angle equal to 1/1000th of a radian.

You may now be asking: “Why are Mils used with rifle scopes and long range shooting?”

Great question! 

However, before we get into why (and how) Mils are used for shooting rifles, we need to first improve our understanding a bit more about what a Milliradian is.

The first thing to understand about Milliradians is that they are angular and not a linear measurements.

What does that mean?

It means that a Milliradian is just like any other angular measurement… it can only refer the the angle between two things and NOT a length. The same thing is true about Minutes of Angle.

If that confuses you, or at least makes you wonder why that matters, let me explain it a little.

Here’s how I like to explain Milliradians (just like I do in the video below and in the Long Range Shooting Handbook):

Milliradians Explained

There’s a certain beauty in using Mils over Minutes of Angle. I learned on MOA but I’m a bit old school. If I were starting over again today, I’d commit to and learn Mils.

Why?

Here’s the simplicity of using Milliradians: Imagine yourself standing at the center of the circle in the diagram above and you spread two laser pointers 1 Milliradian apart and shine them along the radius to the edge of the circle (“A” distance), then the dots will spread exactly 1/1000th of the length of the radius (“A” distance) apart.

Remember, that’s because (B) is the same length as (A) and we have chopped (B) into 1,000 title chunks to get one Mil. Therefore, 1 Mil is always 1/1,000th of whatever distance.

I have heard many people argue over whether 1 Milliradian equals 1 meter at 1000 meters or whether it equals 1 yard at 1000 yards.

They are both right!

1 Milliradian equals 1/1000th of ANY distance.

One Mil is 1 inch at 1000 inches and 1 mile at 1000 miles. It doesn’t matter what unit of measurement you are using as long as you keep using that unit of measurement.

This means that 1 Mil is exactly 10 centimeters (cm) at 100 meters (m), 20 cm at 200 m, 30 cm at 300 m, and so on.

Let’s do the math to see if that check out: Because we are dealing with the metric system, we can simply move the decimal place from 100.0 meters to the left 3 places to find 1/1000th. Moving the decimal three positions to the left in 100.0 meters results in 0.1000 meters (1/10th of a meter). Because there are 100 cm in a meter, 1/10th of a meter is 10 cm.

Most scopes with Mil turrets adjust in 0.1 (1/10th) Mil increments (0.1 Mil per “click”). If 1 Mil is 10 cm at 100 meters, then 1/10th of a Mil is 1 cm at 100 meters. Therefore a single 0.1 Mil adjustment on a Mil scope will move the bullet impact 1 cm per 100 meters.

Understanding Mils Video

Here’s a video of a much younger me explaining Mils:

How to Use Milliradians

If you want to use your Milliradian scope effectively, I ask you to consider using my “trick.”

Once I know the distance at which I am shooting (or the distance at which the shooter is shooting if I’m spotting), I immediately determinate how big 1/10th of a Mil will be at that distance.

If I’m working with MOA, I use the same trick but I just imagine how big 1 MOA is at that distance.

For example, if I am shooting at 600 meters, I know that 1/10th of a Mil is 6 cm at that distance. Therefore, I start thinking in 6 cm “chunks.”

If the bullet impacts 12 cm low, I know that I need to adjust up 2/10ths of a Mil (0.2 Mil) because two 6 cm “chunks” fit within the 12 cm adjustment I need.

When you are zeroing your rifle, or otherwise shooting at 100 meters, you now know that 0.1 Mil is 1 cm at that distance. Therefore, whenever you need to make an adjustment, you should ask yourself how many 1 cm “chunks” are needed to adjust your bullet impact to where you want it to be. The resulting answer is how many 1/10ths of a milliradian you need to adjust on you Mil scope.

You might have noticed that I’m using centimeter adjustments and meters for target distance. You may need to convert your numbers.

If you know the target distance in yards and you need it in meters, just subtract 10% of the distance to convert yards to meters. e.g. I have a distance of 600 yards and I need it in meters. 10% of 600 is 60. If I subtract 60 from 600, I am left with 540. Therefore 600 yards = 540 meters.

Likewise, you might have inches and need centimeters. To convert inches to centimeters, you multiply the inches times 2.54 to get a result in centimeters.

Mil vs MOA

So, which is better, Mils or MOA?

That’s nearly impossible for me to answer for you.

I mostly use MOA for my long range shooting but that’s because I have many MOA scopes and many tax payer dollars have been spent teaching me MOA.

However, Mil is a superior system and I would recommend most new shooters start with Mil with one caveat: if you have a group of shooting buddies that you’ll shoot long range with and they all shoot MOA, then you might want to start with MOA to be able to learn using a common language with them.

For a breakdown of the two systems and pros and cons of each, check out our article: Mils vs MOA.

Note: the decision between using Mil or MOA needs to happen BEFORE you purchase your scope. This is not something you can decide later.

For example, if you purchase a scope that adjusts in Milliradians, then you need to use Mils for your calculations and adjustments on your rifle scope.

If you later decide that you’d rather use MOA, then you need to get a MOA scope.

Long Range Shooting Handbook

A Beginner’s Guide to Precision Rifle Shooting
Long Range Shooting Handbook

This topic, and many more long range shooting topics, are covered in the best-selling Long Range Shooting Handbook.

Mil Formulas and Calculations

Here are some formulas you can use when working with Mils while shooting:

Simple Mil Formulas:

Meters to Target / 100 = centimeters per 0.1 Mil adjustment at that distance

Centimeters of Adjustment Needed / Size of 0.1 Mil Chunk in centimeters = 0.1 Mil adjustment

Clicks per Mil on Scope x Number of Mil Adjustment Needed = Number of Clicks Needed for Adjustment

Mil Calculations:

Mils -> MOA: Mils * 3.438 = MOA

Mils -> centimeters per 100 meters: Mils x 10 = centimeters per 100 meters

Inches -> Centimeters: Inches * 2.54 = Centimeters

Yards -> Meters: Yards – 10% = Meters

To see a table with these calculations, check out the MOA table at the bottom of this article.

What is a Mil? QUIZ

If you’d like some practice to ensure that you understand what Mils are, here you go!

How many Mils is 3 centimeters at 300 meters?

It is 1/10th (0.1) Mil. Remember, because Mils are an angular measurement, it’s linear size gets larger the further away you go… 1/10th of a Mil is 1 cm at 100 meters, 2 cm at 200 meters, 3 cm at 300 meters, and so on.

How many Mils is 12 centimeters at 600 meters?

It is 2/10ths (0.2) of a Mil. If you think in “chunks,” you know that 0.1 Mil is a 6 cm chunk at 600 meters. Two 6 cm chunks fit within the 12 cm size… therefore 0.2 Mil. So, if you measure that your bullet impacted 12 cm low at 600 yards, you’d adjust your turret up 0.2 Mils.

At 25 meters, how far will a bullet’s impact change with an 0.8 Mil adjustment?

2 Centimeters. 0.1 Mils is 0.25 cm at 25 meters and 8 of those 0.25 cm chunks equal 2 cm.

If your scope adjusts 0.1 Mil per click, how many “clicks” are needed to move 2 cm at 100 meters?”

2 clicks.

To solve this, you should first calculate how many Mils are needed – 0.2 Mils are needed to adjust 2 cm at 100 meters. Next, you should note that 1 “click” equals 0.1 Mil therefore 2 “clicks” are needed.

If you’re looking for more discussion on this topic, and more questions and answers, please check out the Long Range Shooting Handbook.

What Are Milliradians? FAQ

Q: How big is 1 Mil at 100 meters?

A: A Mil is 10 centimeters large at 100 meters.

Q: How big is 1/10th of a Mil (0.1 Mil) per 100 meters?

A: 1/10th of a Mil (0.1 Mil) is 1 centimeters per 100 meters.

Q: Are Mil and MOA the same thing?

A: No, Mil and MOA are not the same thing. However, they can be used in the same way as they are both angular measurements. “MOA” is short for Minute of Angle (1/60th of a degree).

Q: What does “Mil” stand for?

A” The term “Mil” is short for Milliradian (1/1000th of a Radian)

Q: What are Mils used for?

A: Mils are used for adjusting a rifle scope either to sight in a rifle (zero) or to engage targets at different distances.

Q: Which can be adjusted on a scope more precisely (finely), MOA or Mil?

A: MOA can be adjusted in finer (smaller/precise) increments than Mils for most scopes. This is because most scopes that adjust in MOA adjust in 1/4 MOA per “click” whereas most Mil scopes adjust in 1/10 Mil per “click.” At 100 yards, 1/4 MOA is 0.25″ whereas 1/10th Mil is 0.36″

Q: How many clicks are 1 Mil increments on my scope?

If you have a Mil scope, it most likely adjusts in 10 clicks for 1 Mil increment. It’s important that you as the shooter know how much of an adjustment on your turret will move your bullet impact.

Mil Table

In this Mil table, we’ve given you easy conversions between Mils and MOA along with their sizes in inches and centimeters at different distances.

If you’d like to convert these numbers on your own, please see the Milliradian Formulas above.

MilsMOACM per 100 metersinches/100 yards (exact)
0.10.3410.36
0.20.6920.72
0.31.0331.08
0.41.3841.44
0.51.7251.80
0.62.0662.16
0.72.4172.52
0.82.7582.88
0.93.0993.24
13.44103.60
1.13.78113.96
1.24.13124.32
1.34.47134.68
1.44.81145.04
1.55.16155.40
1.65.50165.76
1.75.84176.12
1.86.19186.48
1.96.53196.84
26.88207.20
2.17.22217.56
2.27.56227.92
2.37.91238.28
2.48.25248.64
2.58.60259.00
2.68.94269.36
2.79.28279.72
2.89.632810.08
2.99.972910.44
310.313010.80
3.110.663111.16
3.211.003211.52
3.311.353311.88
3.411.693412.24
3.512.033512.60
3.612.383612.96
3.712.723713.32
3.813.063813.68
3.913.413914.04
413.754014.40
4.114.104114.76
4.214.444215.12
4.314.784315.48
4.415.134415.84
4.515.474516.20
4.615.814616.56
4.716.164716.92
4.816.504817.28
4.916.854917.64
517.195018.00
5.117.535118.36
5.217.885218.72
5.318.225319.08
5.418.575419.44
5.518.915519.80
5.619.255620.16
5.719.605720.52
5.819.945820.88
5.920.285921.24
620.636021.60
6.120.976121.96
6.221.326222.32
6.321.666322.68
6.422.006423.04
6.522.356523.40
6.622.696623.76
6.723.036724.12
6.823.386824.48
6.923.726924.84
724.077025.20
7.124.417125.56
7.224.757225.92
7.325.107326.28
7.425.447426.64
7.525.797527.00
7.626.137627.36
7.726.477727.72
7.826.827828.08
7.927.167928.44
827.508028.80
8.127.858129.16
8.228.198229.52
8.328.548329.88
8.428.888430.24
8.529.228530.60
8.629.578630.96
8.729.918731.32
8.830.258831.68
8.930.608932.04
930.949032.40
9.131.299132.76
9.231.639233.12
9.331.979333.48
9.432.329433.84
9.532.669534.20
9.633.009634.56
9.733.359734.92
9.833.699835.28
9.934.049935.64
1034.3810036.00
10.134.7210136.36
10.235.0710236.72
10.335.4110337.08
10.435.7610437.44
10.536.1010537.80
10.636.4410638.16
10.736.7910738.52
10.837.1310838.88
10.937.4710939.24
1137.8211039.60
11.138.1611139.96
11.238.5111240.32
11.338.8511340.68
11.439.1911441.04
11.539.5411541.40
11.639.8811641.76
11.740.2211742.12
11.840.5711842.48
11.940.9111942.84
1241.2612043.20
12.141.6012143.55
12.241.9412243.91
12.342.2912344.27
12.442.6312444.63
12.542.9712544.99
12.643.3212645.35
12.743.6612745.71
12.844.0112846.07
12.944.3512946.43
1344.6913046.79
13.145.0413147.15
13.245.3813247.51
13.345.7313347.87
13.446.0713448.23
13.546.4113548.59
13.646.7613648.95
13.747.1013749.31
13.847.4413849.67
13.947.7913950.03
1448.1314050.39
14.148.4814150.75
14.248.8214251.11
14.349.1614351.47
14.449.5114451.83
14.549.8514552.19
14.650.1914652.55
14.750.5414752.91
14.850.8814853.27
14.951.2314953.63
1551.5715053.99
15.151.9115154.35
15.252.2615254.71
15.352.6015355.07
15.452.9515455.43
15.553.2915555.79
15.653.6315656.15
15.753.9815756.51
15.854.3215856.87
15.954.6615957.23
1655.0116057.59
16.155.3516157.95
16.255.7016258.31
16.356.0416358.67
16.456.3816459.03
16.556.7316559.39
16.657.0716659.75
16.757.4116760.11
16.857.7616860.47
16.958.1016960.83
1758.4517061.19
17.158.7917161.55
17.259.1317261.91
17.359.4817362.27
17.459.8217462.63
17.560.1617562.99
17.660.5117663.35
17.760.8517763.71
17.861.2017864.07
17.961.5417964.43
1861.8818064.79
18.162.2318165.15
18.262.5718265.51
18.362.9218365.87
18.463.2618466.23
18.563.6018566.59
18.663.9518666.95
18.764.2918767.31
18.864.6318867.67
18.964.9818968.03
1965.3219068.39
19.165.6719168.75
19.266.0119269.11
19.366.3519369.47
19.466.7019469.83
19.567.0419570.19
19.667.3819670.55
19.767.7319770.91
19.868.0719871.27
19.968.4219971.63
2068.7620071.99

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About Ryan Cleckner

Ryan is a former special operations sniper (1/75 Ranger) and current firearms attorney, firearms industry executive, university lecturer, and bestselling author of the Long Range Shooting Handbook.

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