MIL vs MOA: which to use and how to convert
MIL and MOA are both angular units for scope adjustments. Here is what each one measures, how they compare at distance, and why picking one system and matching your turret to your reticle matters more than which you choose.
Both are angles, not distances
A rifle scope adjusts in angle, because a fixed angle covers a bigger slice of target the further away it is. Both MIL and MOA are just different ways of slicing up that angle.
- MOA (minute of angle) is 1⁄60 of one degree. At 100 yards it subtends 1.047 inches, which nearly everyone rounds to 1 inch per 100 yards.
- MIL (milliradian) is 1⁄1000 of a radian. It subtends 1 metre at 1000 metres — equivalently 10 cm at 100 m, or 3.6 inches at 100 yards.
Because they are angles, the same figure grows linearly with range: 1 MIL is 10 cm at 100 m, 20 cm at 200 m, 50 cm at 500 m.
How they compare
| 1 full unit | 1 MIL = 3.438 MOA. 1 MOA = 0.291 MIL. |
|---|---|
| Common click value | MIL turrets almost always click in 0.1 MIL. MOA turrets usually click in 1⁄4 MOA (some target scopes use 1⁄8). |
| One click at 100 yd | 0.1 MIL ≈ 0.36 in. 1⁄4 MOA ≈ 0.26 in. |
| Resolution | A 1⁄4-MOA click is slightly finer than a 0.1-MIL click. In practice the difference is trivial next to your ability to call the shot. |
Neither system is more accurate. MOA users like that the numbers relate to inches at 100-yard increments; MIL users like the base-10 arithmetic and that most modern reticles, ammunition data and shooting partners are in MIL.
The rule that actually matters
Your turrets and your reticle must be in the same unit. If your reticle has MIL hash-marks, your turrets must adjust in MIL — then when you see an impact 0.4 MIL low in the reticle, you dial 0.4 MIL up (4 clicks) and you are done. A mismatched scope (MIL reticle, MOA turret, or a “SFP” reticle used at the wrong magnification) forces a conversion under time pressure and is the classic source of missed corrections.
Pick one system, set your range card to show drop in that unit, and use it for everything: dialing, holdovers, wind, and spotting corrections for a partner.
Converting between the two
If you have to convert — reading someone else's data, say — the exact factors are:
- MOA → MIL: divide by 3.438 (or multiply by 0.2909)
- MIL → MOA: multiply by 3.438
Example: a load that needs 6.1 MIL at 800 yards needs 6.1 × 3.438 ≈ 21 MOA. The Ballistic Buddy calculator shows both columns at once so you can check yourself, and every cartridge page lists elevation in MIL and MOA side by side.