How To Calculate MOA: Minute of Angle Formula, Scope Clicks, and Examples
Quick Answer
MOA means minute of angle. One MOA is 1/60 of one degree, and it equals about 1.047 inches at 100 yards. Shooters often round it to “one inch at 100 yards” for fast field math. To calculate MOA, divide the size of the group or point-of-impact correction in inches by the distance in hundreds of yards. If your scope adjusts in 1/4 MOA clicks, multiply the MOA correction by four to get the number of clicks.
- 1 true MOA at 100 yards: 1.047 inches.
- Fast field estimate: 1 inch at 100 yards, 2 inches at 200 yards, 3 inches at 300 yards.
- MOA formula: group size or correction in inches ÷ distance in hundreds of yards.
- 1/4 MOA scope: four clicks equal one MOA.
- Sub-MOA rifle: a rifle that can repeatedly group shots inside one MOA under controlled conditions.
What Is MOA?
MOA stands for minute of angle. It is an angular measurement, not a fixed linear measurement. That distinction matters because one MOA gets larger as distance increases. At 100 yards, one MOA is about one inch. At 500 yards, the same angular measurement covers about five inches. At 1,000 yards, one MOA covers about ten inches.
In practical shooting language, MOA is used for three common tasks:
- Measuring rifle accuracy by the size of a shot group.
- Correcting point of impact when zeroing a rifle scope.
- Using reticle marks or turret adjustments to hold or dial for distance and wind.
Think of MOA as a cone spreading outward from the rifle. The farther the target, the wider the cone becomes.
MOA Formula
For most shooters, the useful MOA formula is:
MOA = inches of correction ÷ distance in hundreds of yards
For a mathematically exact calculation, use 1.047 inches per 100 yards:
MOA = inches of correction ÷ (distance in yards ÷ 100 × 1.047)
For example, if your bullet impact is 4 inches low at 200 yards:
- Distance in hundreds of yards: 200 ÷ 100 = 2
- Field MOA estimate: 4 ÷ 2 = 2 MOA
- With a 1/4 MOA turret: 2 MOA × 4 clicks = 8 clicks
MOA Size by Distance
| Distance | 1 MOA Approximation | 1 True MOA | 1/4 MOA Click Value |
|---|---|---|---|
| 100 yards | 1 inch | 1.047 inches | 0.26 inch |
| 200 yards | 2 inches | 2.094 inches | 0.52 inch |
| 300 yards | 3 inches | 3.141 inches | 0.79 inch |
| 400 yards | 4 inches | 4.188 inches | 1.05 inches |
| 500 yards | 5 inches | 5.235 inches | 1.31 inches |
| 1,000 yards | 10 inches | 10.47 inches | 2.62 inches |
How To Calculate Scope Clicks
Most MOA rifle scopes adjust in fractions of one MOA. The most common adjustment is 1/4 MOA per click, but some scopes use 1/2 MOA, 1/8 MOA, or other values. The click value should be marked on the turret cap or listed in the scope manual.
Use this formula:
Number of clicks = MOA correction ÷ click value
For a 1/4 MOA scope, the formula becomes:
Number of clicks = MOA correction × 4
| Needed Correction | 1/4 MOA Scope | 1/2 MOA Scope | 1/8 MOA Scope |
|---|---|---|---|
| 1 MOA | 4 clicks | 2 clicks | 8 clicks |
| 2 MOA | 8 clicks | 4 clicks | 16 clicks |
| 3 MOA | 12 clicks | 6 clicks | 24 clicks |
| 5 MOA | 20 clicks | 10 clicks | 40 clicks |
Example: Zeroing a Scope With MOA
Suppose you are zeroing at 100 yards. Your three-shot group lands 2 inches low and 1 inch right of the aiming point. At 100 yards, one MOA is about one inch.
- Vertical correction: 2 inches low = 2 MOA up.
- Horizontal correction: 1 inch right = 1 MOA left.
- With 1/4 MOA clicks, dial 8 clicks up and 4 clicks left.
- Fire another group and confirm the correction.
At 200 yards, the same two-inch shift would only be about one MOA because one MOA is about two inches at that distance.
How To Measure a Shot Group in MOA
To measure a group, find the two widest bullet holes and measure from the outside edge of one hole to the outside edge of the other. Then subtract one bullet diameter. This gives the center-to-center group size.
For example, with a .308 rifle:
- Outside-to-outside group measurement: 1.50 inches
- Bullet diameter: 0.308 inch
- Center-to-center group size: 1.50 - 0.308 = 1.192 inches
If that group was shot at 100 yards, it is slightly larger than one MOA. If it was shot at 200 yards, it is about 0.6 MOA.
True MOA vs Shooter’s MOA
True MOA is 1.047 inches at 100 yards. Shooter’s MOA, sometimes called IPHY or inches per hundred yards, rounds the value to exactly one inch at 100 yards. For most hunting and general rifle use, the difference is small. For precision shooting at longer distances, the difference can matter.
| Term | Meaning | Best Use |
|---|---|---|
| True MOA | 1.047 inches at 100 yards | Precision calculations, long-range shooting, confirmed data |
| Shooter’s MOA | 1 inch at 100 yards | Fast field math, rough zeroing, simple range work |
MOA vs MRAD
MOA and MRAD are both angular systems. Neither is automatically better. MOA is common in the United States because many shooters think in yards and inches. MRAD is common in military, tactical, and international use because it works naturally with the metric system.
| System | Common Click Value | Approximate Movement at 100 Yards | Typical User |
|---|---|---|---|
| MOA | 1/4 MOA | 0.26 inch per click | Hunters, American sport shooters, traditional scope users |
| MRAD / MIL | 0.1 MIL | 0.36 inch per click | Precision rifle, tactical, metric-based shooters |
Common MOA Mistakes
- Forgetting distance: one MOA is not always one inch; it scales with distance.
- Dialing the wrong direction: check whether you are moving the point of impact or the reticle, and follow the turret markings.
- Using one shot as proof: groups tell more than single impacts.
- Mixing MOA and MIL: keep turret and reticle units matched whenever possible.
- Ignoring shooter error: group size reflects rifle, ammunition, optic, rest, environment, and shooter consistency.
MOA for Hunting and Thermal Optics
MOA is especially useful when sighting in a day scope, thermal scope, or digital optic. The same angular math applies whether you are adjusting a traditional rifle scope or a thermal weapon sight. If your impact is four inches low at 100 yards and your optic uses 1/4 MOA adjustments, you still need about 16 clicks up.
For AGM optics, always confirm the exact adjustment unit in the manual for your specific model. Some devices use MOA, some use digital reticle movement, and some may display adjustment values differently depending on the shooting profile or zeroing menu.
Related AGM categories:
FAQ
What does MOA stand for?
MOA stands for minute of angle. It is an angular measurement equal to 1/60 of one degree.
How many inches is 1 MOA at 100 yards?
One true MOA is 1.047 inches at 100 yards. Shooters often round that to one inch for fast field math.
How many clicks is 1 MOA?
That depends on the scope. On a 1/4 MOA scope, one MOA equals four clicks. On a 1/2 MOA scope, one MOA equals two clicks.
What is a sub-MOA rifle?
A sub-MOA rifle can repeatedly shoot groups smaller than one MOA under controlled conditions. At 100 yards, that means groups smaller than about 1.047 inches.
Is MOA better than MRAD?
Not necessarily. MOA is convenient for shooters who think in yards and inches. MRAD is convenient for shooters who prefer metric calculations or use MIL-based reticles and turrets.
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