Firearm Faceoff: MRAD vs. MOA

Minutes Of Angle, or MOA, is a measurement that expresses fractions of a degree. It may sound like it’s trying to measure angles in time (e.g. “minutes”) but that’s not the case. MOA uses the 360 degrees in a circle and divides those individual degrees by 60. Each degree therefore has 60 individual “minutes” – making for 21,600 minutes in a 360 degree circle. One minute of angle is – you guessed it – 1/60th of one degree

This approach is based in a sexagesimal system, which originated from the ancient Sumerians in the 3rd millennium BC. We’re used to a base 10 system, so the base 60 feels a little arbitrary, but it’s certainly a functional standard of measurement for these purposes.

A way to visualize this is if the tip of your firearm’s barrel is the center of a circle which stretches 100 yards around you in every direction. If you have a target exactly 100 yards in front of you, that target would be at zero degrees. If you then measured up from your zero degree target a single degree that distance would measure 62.83 inches at 100 yards. 

This means that 1 degree of angle at 100 yards measures 62.83 inches. Following?

If we further subdivide that 62.83 inches by the 60 minutes in a degree, we get 1.047 inches per minute. So one MOA at 100 yards is almost exactly one inch. This is why we use 1-inch grids for sighting in a rifle with a MOA-based scope. At 100 yards, a sub-MOA grouping is evident when all shots are within a single square of the grid. Easy stuff!

The beauty of this simple 1-MOA-per-100-yard concept is that it stays consistent per 100 yards – 1 MOA at 500 yards is 5.235 inches, at 1,000 yards is 10.47 inches.

MOA informs the point-of-aim shift we need to use to compensate for the bullet drop which occurs from the barrel to the point of impact. 

To illustrate MOA in action, here are some assumptions that will help: 

• MOA turrets adjust in ¼ MOA increments – scopes don’t adjust in full MOA increments – they adjust at a ratio of ¼ MOA per click. The below table demonstrates the amount of change to the point of impact a single MOA adjustment will make at various distances.
• Bullet drop of 1 inch per 100 yards holds true at longer distances – as we detailed above a 1.047-inch-per-100-yards is technically more accurate, but adjusting our measurement to “shooter’s MOA” simplifies things by rounding down to the nearest inch.

MOA Measurement:       

Point of Impact Change Per Scope Click:

100 yards = 1.0 inch

100 yards = 0.25 inch

200 yards = 2.0 inch

200 yards = 0.50 inch

300 yards = 3.0 inch

300 yards = 0.75 inch

400 yards = 4.0 inch

400 yards = 1.00 inch

500 yards = 5.0 inch

500 yards = 1.25 inch

600 yards = 6.0 inch

600 yards = 1.50 inch

700 yards = 7.0 inch

700 yards = 1.75 inch

800 yards = 8.0 inch

800 yards = 2.00 inch

900 yards = 9.0 inch

900 yards = 2.25 inch

1000 yards = 10.0 inch

1000 yards = 2.50 inch

The key takeaway here is that the MOA system is based around inches, and thus will be more comfortable for those of us familiar with the Imperial system.

MRAD, or MiliRadians, is also a mathematical measurement of angular difference, similar to MOA, but based on the metric system (technically the International Standard of Measurements). The difference is the unit of measurement. 

MOA uses minute of angle, of which there are 21,600 in a 360 degree circle. MRAD  divides that same circle into 6.283 radians – each radian is then subdivided into 1,000 milliradians, giving us 6,283 milliradians per 360 degree circle.

You’ll often find the mil system in both military and law enforcement applications, as well as shooters outside of the U.S.The general rule of thumb is that for every 100 meters your bullet flies, it will drop 10 centimeters. At 100 yards, one mil is about 3.6 inches (or just under 10 cm). If you’ll recall – 1 MOA measures just over 1 inch at 100 yards. At 500 yards, 1 mil is 18 inches., and at 1,000 yards, 1 mil is 36 inches.

The simplicity of the base-10 MRAD system is a big part of its appeal.

Like MOA, we’ve provided a chart to give you some guidance for zeroing your scope at a variety of ranges.

MRAD Adjustments       

Point of Impact Change Per Scope Click

100 meters = 10 cm

100 meters = 1.0 cm

200 meters = 20 cm

200 meters = 2.0 cm

300 meters = 30 cm

300 meters = 3.0 cm

400 meters = 40 cm

400 meters = 4.0 cm

500 meters = 50 cm

500 meters = 5.0 cm

600 meters = 60 cm

600 meters = 6.0 cm

700 meters = 70 cm

700 meters = 7.0 cm

800 meters = 80 cm

800 meters = 8.0 cm

900 meters = 90 cm

900 meters = 9.0 cm

1000 meters = 100 cm

1000 meters = 10.0 cm

The takeaway here is that MRAD functions the same as MOA, simply in centimeters rather than in inches.

There’s no “best” system between the two. Both have long and interesting histories, but it’s helpful to keep a few key things to keep in mind when choosing which system would work best for you. 

First, there is something to be said about personal preference between mil and MOA scopes. Your familiarity with the base system matters the most: if you’re more comfortable working in inches, then go with MOA.  If you’re more comfortable working with the metric system, then MRAD is the way to go. 

It’s also important to consider coordinating your ranging with what others use. If, for example, you’re zeroing with a spotter, make sure you’re using a common system, otherwise you’ll be doing field conversions to zero accurately, and nobody likes doing math while their prey gets away.

The thing that will get you in trouble here is the same thing that messed with us in chemistry class: mixing units. Make sure that when you are zeroing a rifle that you, and your spotter, are on the same system. MOA and MRAD measure the same thing, but use languages.

In terms of precision, there are a few interesting differences. Using our 100 yard example, and assuming a ¼ MOA per click adjustment, we see that 1 click on a MOA scope works out to about 0.25 inches at 100 yards, while mil scope adjustments are divided by tenths – which gives us 0.36 inches at 100 yards.

This means a MOA scope is, on average, more precise in its adjustments. While this may not matter much in a practical sense, for ultra long range shooters (or competitions) these differences can make or break your shot.

Of course, with training and dedication you can certainly become proficient with both systems.

There are awesome scopes made for both MOA and MRAD, and we’re certainly not going to leave you high and dry when it comes to recommendations. Here are a few of our favorites.

The Strike Eagle is quickly becoming one of the go-to optics on ARs these days, thanks to the fact that it is adjustable from 1x-8x zoom on the fly. That makes it awesome for hunting as well as for competitions. We like the ARBDC3 reticle, which we think is one of the best MOA reticles out there today for quickly dialing in shots.

MOA Scopes: Vortex Razor

The Razor is one of our favorite optics: the MOA dot reticle is super easy to follow, and the build quality is something to behold. Yes, you pay for it, but if we were making our dream hunting rifle build, this scope would likely be on it. It’s built to withstand the toughest conditions you can throw at it.

MRAD Scopes: Vortex Razor MRAD

The Razor also comes with an MRAD reticle with the same excellent features and build quality. It is the same scope, but with a metric reticle rather than an inch one: we included it to show that both systems are more than at home in high-quality optics. 

4. Premium Option

Sig, long since known for awesome handguns, has been getting into the optics game in recent decades and we think this MRAD scope is a great example of what they can do. Another adjustable scope, this one has a highly visible illuminated reticle that we think would make it an excellent MRAD optic should you want to do some shooting in potentially poor lighting conditions.

MOA and MILRAD are both standard systems of angular measurement – and while they use different means of arriving at a common end (hit the target!) they can both be used with remarkable precision to successfully produce consistent performance at the range. There are some meaningful differences between MRAD and MOA, but they do not offer a major advantage over one another. It may be easier for you to adjust .25MOA, but MRAD is a little easier to communicate thanks to its being in metric. Use the system that works best with your brain, and you will get good results downrange.

1. Minute and second of arc

1. Wikipedia article, Minute and second of arc
2. Wikipedia article, Sexagesimal
3. Wikipedia article, Milliradian
4. Sniper Country, MRAD Vs. MOA Rifle Sighting: The Only Article You’ll Need
5.  Wikipedia article, Long range shooting
6. Wikipedia article, External ballistics