What Is MOA on a Red Dot Sight?

MOA on a red dot sight stands for Minute of Angle. It is a unit of angular measurement that tells you two things: how big the dot appears in your optic and how much each adjustment click moves your point of impact. This page stays on that measurement: the angle, the inches it covers at a yardage, and what a turret click moves.

This guide is by Aaron Rice, General Manager of Ozark Armament. Aaron has tested every optic in the Ozark lineup across 10+ years of AR-15 builds and range sessions.

What Does MOA Actually Mean?

One MOA equals 1.047 inches at 100 yards. Most shooters round it to 1 inch at 100 yards because the difference is less than half a tenth of an inch. At 50 yards, 1 MOA is about half an inch. At 200 yards, it is about 2 inches.

The reason MOA scales with distance is that it is an angle, not a fixed measurement. Picture a flashlight beam. Close to the lens, the beam is tiny. Farther away, it spreads out. MOA works the same way. The dot in your red dot sight covers a specific angle, and that angle translates to more inches of target the farther you shoot.

The Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) defines 1 MOA as exactly 1/60th of 1 degree of angle, which works out to 1.0472 inches at 100 yards. SAAMI recognizes MOA as one of the two standard angular measurements in U.S. firearm optics. The other is MRAD (milliradians), which is more common on long-range rifle scopes.

How MOA Describes the Dot on a Red Dot Sight

When a red dot says "4 MOA," it means the dot covers 4 inches of your target at 100 yards. A 2 MOA dot covers 2 inches. A 6 MOA dot covers 6 inches.

Here is that same angle in inches at 50, 100, and 200 yards:

• 2 MOA dot: 1 inch at 50 yds, 2 inches at 100 yds, 4 inches at 200 yds
• 4 MOA dot: 2 inches at 50 yds, 4 inches at 100 yds, 8 inches at 200 yds
• 6 MOA dot: 3 inches at 50 yds, 6 inches at 100 yds, 12 inches at 200 yds

I zeroed our Rhino Red/Green Dot (4 MOA) at 50 yards on a steel silhouette. The dot sat right inside the 8-inch gong. At 25 yards, the dot looked tiny on the plate. At 100, it covered most of the center zone. Same dot, same optic. Distance just changes how much target it obscures.

Those figures are the geometry only. The separate question of which rating to buy is covered in which dot size is right for you: 3 MOA vs 6 MOA.

What Are MOA Clicks on a Red Dot?

MOA clicks are the adjustment increments on your red dot's windage and elevation turrets. When you turn those dials to zero your red dot, each click moves the point of impact by a set amount.

Most red dot sights use 1 MOA per click. That means each click moves your bullet impact 1 inch at 100 yards, or half an inch at 50 yards. Some higher-end optics use 1/2 MOA clicks for finer adjustments. Budget optics sometimes use 1 MOA clicks but are not always precise to exactly 1 inch. That is why you confirm zero with live fire instead of just counting clicks.

Here is a quick example. You are zeroing at 50 yards and your group lands 3 inches right. Each click moves impact 0.5 inches at 50 yards. So you need 6 clicks left on the windage turret. Shoot another group, check the result, and fine-tune from there.

When I zeroed my first red dot at an indoor range in 2014, I sat there with a calculator trying to figure out fractional MOA adjustments. Total waste of time. Now I just remember: 1 click equals 1 inch at 100, half an inch at 50. That rule gets you on paper in three rounds. From there, it is just small corrections. If you want to see exactly where your bullet lands at every distance for your specific setup, try our zero distance calculator.

MOA vs MRAD: Which System Is on Your Red Dot?

Almost every red dot sight on the market uses MOA for both the dot's angle and the click adjustments. MRAD (milliradians) is more common on magnified rifle scopes used for long-range precision shooting. If you are shopping for a red dot, you are almost certainly looking at MOA specs.

The practical difference: 1 MOA equals about 1 inch at 100 yards. 1 MRAD equals about 3.6 inches at 100 yards. MRAD works in multiples of 10, which makes ballistic math easier at extreme distances. For red dot range (0 to 200 yards), MOA is simpler because you can think in inches.

If you are running a red dot on an AR-15, do not worry about MRAD. It will not come up unless you step into long-range bolt gun territory. I have used MRAD turrets on a bolt gun at 600 yards and MOA turrets on every red dot I have owned. For anything inside 200 yards with a non-magnified optic, MOA keeps things simple.

MOA on Red Dot Sights: Common Questions

Q: What does MOA stand for on a red dot sight?

A: MOA stands for minute of angle. One MOA is 1/60 of one degree. SAAMI states that as 1.0472 inches at 100 yards. On a red dot, the same unit describes the angle the dot subtends and the shift each windage or elevation click gives the point of impact.

Q: What is a 2 MOA red dot at 100 yards?

A: A 2 MOA red dot subtends about 2 inches at 100 yards. At 50 yards that is about 1 inch. At 200 yards it is about 4 inches. The angle does not change. The yardage changes how many inches of target sit inside it.

Q: How much does one MOA click move a red dot?

A: A 1 MOA click moves point of impact about 1 inch at 100 yards and about half an inch at 50 yards. A 1/2 MOA click moves half of that. Read the click value on the turret or in the manual, then confirm the shift on a target.

Q: Do red dots use MOA or MRAD?

A: Nearly all red dots are marked in MOA. MRAD, short for milliradian, is the other angular unit and is more common on magnified long-range scopes. At 100 yards, 1 MOA is about 1 inch and 1 MRAD is about 3.6 inches.

MOA on a Red Dot Sight, in Short

MOA on a red dot is an angle: 1/60 of a degree, about 1.05 inches at 100 yards. That angle is what the reticle spec measures, and it is what each turret click moves. Stretch the yardage and the same angle covers more inches. Count the clicks and the impact walks toward the point of aim.

ARTICLE WRITTEN BY AARON RICE, GENERAL MANAGER OF OZARK ARMAMENT