MOA vs MIL: Which System for Precision Rifle Work (angular units, not measurements of distance)

MOA and MIL are the two units precision shooters argue about the way carpenters argue about metric vs imperial. Both work. Neither is more accurate. The choice is about how you think, what your shooting partners run, and how you want to do the math when you're behind the rifle.

§ 01What Each Unit Actually Is

Both MOA (Minute of Angle) and MIL (Milliradian) are units of angle, not units of distance. That's the fact everything else follows from. A scope adjusts the angle of the line of sight — it doesn't measure inches at any specific range. The linear result is a function of the angle and the distance to the target.

1 MOA is 1/60th of a degree of arc. At 100 yards, 1 MOA subtends 1.047 inches — close enough to one inch that shooters colloquially call it 'one inch at 100 yards,' even though it isn't quite. At 1,000 yards, 1 MOA subtends 10.47 inches.

1 MIL is 1/1000th of a radian. At 100 yards, 1 MIL subtends 3.6 inches. At 1,000 yards, it subtends 36 inches — exactly 1 yard. In metric, 1 MIL is 10 centimeters at 100 meters, or 1 meter at 1,000 meters. That unit relationship — 1 MIL at range = 1/1000th of range — is what makes MIL native to metric ranging math.

Turrets on modern scopes are typically graduated in 1/4 MOA clicks (0.25 MOA per click) or 0.1 MIL clicks. A 1/4 MOA click moves impact roughly 0.26 inches at 100 yards. A 0.1 MIL click moves impact 0.36 inches at 100 yards. MIL clicks are coarser; MOA quarter-clicks are finer.

§ 02The Math, Enough of It

The math you actually need at the rifle is small.

To hold or dial from a range-solved value

The solver gives you a number in the unit your reticle and turret share. You dial that number, or hold it on the reticle. That's the whole workflow. As long as the reticle and turret match, no conversion is required.

To convert MOA ↔ MIL when you have to

1 MIL ≈ 3.438 MOA. A 10 MIL correction is roughly 34.4 MOA. It works the other way too: 10 MOA is about 2.91 MIL. Serious shooters memorize the conversion because they'll hear both from partners in a match.

To range a target of known size

With a MIL reticle: range in yards = (target size in inches × 27.78) ÷ mils read. A 20-inch target that appears 2 mils tall in the reticle: (20 × 27.78) ÷ 2 = 278 yards.

With an MOA reticle: range in yards = (target size in inches × 95.5) ÷ MOA read. The same 20-inch target appearing 7 MOA tall: (20 × 95.5) ÷ 7 = 273 yards.

§ 03When to Choose MOA

MOA is a defensible choice, and in some cases the correct one, when:

• Your existing rifle scopes are MOA and buying compatible glass keeps the system consistent
• You shoot at ranges where 1/4-inch precision at 100 yards matters — smallbore, benchrest, some hunting
• Your target sizes, group measurements, and holdovers are already expressed in inches
• Your shooting partners run MOA and communal callouts stay in one unit

MOA is native to inches-and-yards thinking. A 3-inch group at 100 is a 3 MOA group. A 10-inch target at 500 is 2 MOA. The math scales in a way American shooters raised on imperial units find intuitive.

The critique of MOA — that 1/4 MOA clicks are 'too fine' for practical work at range — has some merit at extreme distance. Dialing 31 MOA of elevation for a 1,000-yard shot involves 124 clicks. On a fast turret, it's fine. On a slow one, it's tedious. For general precision-rifle work, 1/4 MOA is a feature, not a bug.

§ 04When to Choose MIL

MIL is the correct choice, and increasingly the dominant one in competition, when:

• You're new to precision rifle and can pick either — MIL is the current standard in PRS, NRL, and most military applications
• You shoot with a solver, a rangefinder, and partners who all speak MIL
• You want coarser clicks (0.1 MIL) that move you through elevation faster with fewer turns
• You do any metric-range shooting where MIL's clean 1-to-1000 relationship simplifies math

MIL's dominance in competition isn't accidental. In a match with 90-second stages and multiple targets, dialing 4.6 MIL of elevation is faster than dialing 15.7 MOA. Partner communication is faster in MIL — 'come left, three-tenths' beats 'come left, one MOA'. Ranging math is faster in metric.

The critique of MIL — that 0.1 MIL clicks are too coarse for the finest precision — is real for some disciplines. A 0.1 MIL click is 0.36 inches at 100 yards; a 1/4 MOA click is 0.26 inches. For a benchrest shooter measuring groups in thousandths, that granularity matters. For a PRS shooter engaging a 10-inch plate at 800 yards, it doesn't.

§ 05Mixing Units — Don't

The one rule both camps agree on: your reticle and your turret should be in the same unit. MIL reticle, MIL turret. MOA reticle, MOA turret. This is not a preference — it's a requirement for the workflow of 'range the target, solve, dial, hold' to function at speed.

The failure mode of a mismatched system is subtle. A shooter with an MOA turret and a MIL reticle who sees a miss 1 MIL low can't dial 1 MIL on the turret — they have to convert to 3.4 MOA and dial that. Every correction becomes a math problem, and the shooter under time pressure will get one of them wrong.

If you're building a rifle from scratch and have no legacy glass to match, MIL is the current default and the correct one for most precision-rifle applications. If you already run MOA and it's working, staying in MOA is the correct one. There is no third option worth having.