MIL vs MOA

Short version: MOA and MIL are both units of angle. They describe how big a sight adjustment is, or how big a group looks at distance. MOA is 1/60th of a degree. MIL is 1/1000 of a radian. At 100 yards, 1 MOA ≈ 1″ and 1 MIL ≈ 3.6″.

Distance300 yds

505001,0001,500 yds

1 MOA

3.1in

8.0 cm

1 MIL

10.8in

27.4 cm

At 300 yards, a 1-MOA group spans roughly 3.1″ and a 1-MIL adjustment moves point-of-impact 10.8″. Most scopes adjust in 1/4 MOA or 0.1 MIL clicks — that's 0.79″ per MOA click or 1.08″ per MIL click at this distance.

The actual math

Both MOA and MIL are angular measurements, which means their linear size (in inches or centimeters) grows with distance. The numbers worth memorizing:

1 MOA = 1.047″ at 100 yards. So at 200 yards it's ~2.1″, at 500 yards ~5.2″, at 1,000 yards ~10.5″.
1 MIL = 3.6″ at 100 yards. At 200 yards that's 7.2″, at 500 yards 18″, at 1,000 yards 36″.
1 MIL = 1/1000 of distance. At 100 m, 1 MIL = 10 cm. At 500 m, 1 MIL = 50 cm. This is why MIL is the cleaner unit for metric-system math.

MOA vs MIL — head-to-head

	MOA	MIL
Subtension at 100 yds	1.047″	3.6″
Typical click value	1/4 MOA (0.26″ at 100)	0.1 MIL (0.36″ at 100)
Clicks per inch at 100 yds	~3.8	~2.8
Range estimation	Awkward (inches/yards)	Clean (meters)
Common in	US hunting, NRA F-Class	Military, PRS, NATO

Which should you choose?

Pick MOA if: most of your shooting is in inches and yards, you grew up with American hunting culture, your group sizes get described as "sub-MOA" or "1 inch at 100 yards." The math feels natural.

Pick MIL if: you shoot or compete in metric distances, you do range estimation from the reticle, you want cleaner math in your head, or you're running gear alongside military/PRS shooters. Most modern tactical/precision optics ship in MIL by default.

The rule that matters more than which one: your reticle, your turrets, and any dope you write down all need to be in the same unit. Mismatched MIL/MOA gear is the most common scope-buying mistake.

Range estimation with MIL

This is the one place MIL is genuinely better than MOA. If you know the target's size and you can measure it in mils on your reticle:

Distance (yards) = (target size in inches × 27.78) ÷ target size in mils
Distance (meters) = (target size in meters × 1000) ÷ target size in mils

A 36-inch IPSC silhouette that subtends 1 MIL on your reticle is exactly 1,000 yards away. A 0.5 m target at 1 MIL is exactly 500 m away. Clean.

Common mistakes

Mismatched reticle and turrets. MIL reticle + MOA turrets means you can't directly dial what you see. Always match.
Treating 1 MOA as exactly 1 inch. Fine inside 200 yards, sloppy beyond. Use 1.047 if you're writing a ballistics app or building a dope card.
Confusing MIL with MILdot. "Mil-dot" refers to a specific reticle pattern with dots spaced at 1 MIL intervals. The math is the same; the dots just give you visual reference points.

Frequently asked

Is MIL more accurate than MOA?

No. They describe the same thing in different units. MIL has slightly more 'real estate' per click (0.1 MIL ≈ 0.36 inches at 100 yards) versus MOA (0.25 MOA ≈ 0.26 inches at 100 yards), so MOA is technically a finer adjustment. In practice, the difference is irrelevant — both are far more precise than the shooter.

Which is easier for beginners — MIL or MOA?

MOA is more intuitive if you think in inches and yards (1 MOA ≈ 1 inch at 100 yards). MIL is more intuitive if you think in the metric system or do math in your head (1 MIL = 1/1000 of distance — at 500 m, 1 mil is exactly 0.5 m). Pick the unit your scope, reticle, and turrets all use. Mismatched units (MIL turrets + MOA reticle) is the most common mistake.

Why do military and police often use MIL?

MIL plays well with the metric system, makes range estimation easier (target size in meters × 1000 ÷ size in mils = distance in meters), and is what most allied militaries standardized on. Most modern precision rifle competitors also use MIL because the math is cleaner.

Should my reticle and turrets match units?

Yes — always. If your reticle is in MIL, get MIL turrets (most modern tactical scopes). If your reticle is in MOA, get MOA turrets. A mismatched scope means you can't directly translate what you see in the reticle into a turret adjustment. This is the single most common scope-buying mistake for new shooters.

What does '1/4 MOA' or '0.1 MIL' clicks mean?

It's the smallest increment of adjustment per click of your turret. 1/4 MOA per click is the most common factory setting — at 100 yards, one click moves point-of-impact about 0.26 inches. 0.1 MIL per click is the most common 'tactical' setting — at 100 yards, one click moves point-of-impact about 0.36 inches.

Why is 1 MOA not exactly 1 inch at 100 yards?

Because 1 MOA = 1/60 of a degree = tan(1/60°) × 100 yards ≈ 1.047 inches. Treating it as 1 inch is fine for back-of-envelope work, but past a few hundred yards the error adds up. Most ballistic apps use the exact 1.047 value.