Scope Adjustment Calculator
Convert inches off target at any distance to MOA, mils and turret clicks, with the exact conversions rather than the common approximations.
Turn the turret in the direction printed on it that moves impact toward center — the math is the same up/down or left/right.
MOA ↔ mil quick reference
| 100 yd | 200 yd | 300 yd | 500 yd | |
|---|---|---|---|---|
| 1 MOA covers | 1.05″ | 2.09″ | 3.14″ | 5.23″ |
| 1 mil covers | 3.60″ | 7.20″ | 10.80″ | 18.00″ |
The two angular systems, exactly: 1 MOA = 1.047″ per 100 yards (many shooters round to 1″), 1 mil = 3.6″ per 100 yards, and 1 mil = 3.44 MOA — conversions verified in tests. Neither is "better"; matching your turret to your reticle is what matters, and mixing a mil reticle with MOA turrets is how ranges stay entertaining.
A minute of angle is not an inch
A minute of angle is a sixtieth of a degree, and at 100 yards it subtends 1.047 inches. The shooting world rounds that to "one inch at a hundred yards". The relative error never changes — it is fixed at 4.7% — but what 4.7% is worth does not stay still.
| Distance | 1 MOA really is | The shortcut says | Short by |
|---|---|---|---|
| 100 yd | 1.05″ | 1.00″ | 0.05″ |
| 200 yd | 2.09″ | 2.00″ | 0.09″ |
| 300 yd | 3.14″ | 3.00″ | 0.14″ |
| 500 yd | 5.24″ | 5.00″ | 0.24″ |
| 800 yd | 8.38″ | 8.00″ | 0.38″ |
| 1000 yd | 10.47″ | 10.00″ | 0.47″ |
At a hundred yards it is inside the group and nobody can see it. At a thousand it is half an inch of correction on top of every other error — and it is systematic rather than random, because the shortcut always understates and never overstates.
The turret is a staircase, and the steps get taller
The correction above is a continuous number. The turret is not — it moves in clicks, and this tool rounds to the nearest one. A click is an angle, so what it is worth in inches grows in exact proportion to the distance.
| Distance | 1/8 MOA | 1/4 MOA | 1/2 MOA | 0.1 mil |
|---|---|---|---|---|
| 100 yd | 0.13″ | 0.26″ | 0.52″ | 0.36″ |
| 200 yd | 0.26″ | 0.52″ | 1.05″ | 0.72″ |
| 400 yd | 0.52″ | 1.05″ | 2.09″ | 1.44″ |
| 600 yd | 0.79″ | 1.57″ | 3.14″ | 2.16″ |
| 1000 yd | 1.31″ | 2.62″ | 5.24″ | 3.60″ |
One click first moves the group more than a full inch at 1/8 MOA 764 yd, 1/4 MOA 382 yd, 1/2 MOA 191 yd, 0.1 mil 278 yd.
| Distance | Worst gap between what you want and what the turret can do | Half a click |
|---|---|---|
| 100 yd | 0.13″ | 0.13″ |
| 300 yd | 0.39″ | 0.39″ |
| 600 yd | 0.79″ | 0.79″ |
| 1000 yd | 1.31″ | 1.31″ |
The two columns are the same number, which is the point: on a quarter-MOA turret the worst you can be left with is half a click, and at 1,000 yards that is 1.31 inches. The scope's own resolution is a bigger error out there than the minute-versus-inch confusion above, and it is the one nobody argues about.
A quarter-MOA click is finer than a tenth-mil click
This surprised me. Mils sound like the precise modern option and 0.1 sounds finer than 0.25, but the units are different sizes: 0.25 MOA is 0.2617 inches at 100 yards and 0.1 mil is 0.36.
The mil turret steps 38% coarser. That is not an argument for MOA — a mil turret matched to a mil reticle lets you read a miss and dial it without arithmetic, which is worth more than a third of a click. But if someone tells you mils are finer, they are not.
And a small enough miss correctly rounds to nothing
Because the tool rounds to the nearest click, any correction under half a click comes back as zero clicks. On a quarter-MOA turret:
| Distance | Groups off by up to this get "0 clicks" |
|---|---|
| 100 yd | 0.13″ |
| 200 yd | 0.26″ |
| 400 yd | 0.52″ |
Same half-click as the table above, for the same reason. It is the right answer and it looks like a broken one: the tool is telling you the scope has no adjustment small enough to be worth making, which is usually the correct thing to hear after a three-shot group.
How to use
- Enter how far off you are and at what distance.
- Choose your turret units and click value.
- Read the number of clicks to adjust.
- Verify with a group rather than a single shot.
Frequently asked questions
What is a minute of angle exactly?
One sixtieth of a degree, which subtends 1.047 inches at 100 yards — not exactly one inch, though it is almost universally rounded to it. The difference is negligible at 100 yards and becomes real at distance: at 1,000 yards it is over half a foot.
What is a mil?
A milliradian, which subtends 3.6 inches at 100 yards, or conveniently one metre at 1,000 metres. Mils suit metric thinking and are the standard in much military use; MOA gives finer adjustment per click on typical scopes. Neither is better, but mixing a mil reticle with MOA turrets is a genuine source of error.
How many clicks do I need?
It depends on your turret's click value — commonly a quarter MOA or a tenth of a mil. The calculation is the correction needed in your unit divided by the click value. Getting this wrong by a factor of four is common enough that checking the turret marking is worth doing.
Should I adjust from a single shot?
No. Shoot a group of three to five and adjust from its centre, since a single shot tells you nothing about where the rifle is pointing on average. Adjusting from one shot chases dispersion around the target and can take a session to undo.
Why did my adjustment not move the point of impact correctly?
Common causes are a scope at the end of its adjustment range, loose mounts, or tracking error in the scope itself. A box test — adjusting a known amount in each direction and returning — reveals whether the turrets track accurately, and some scopes do not.
Does the correction change with distance?
The angular correction does not, which is the point of angular units — 1 MOA is 1 MOA at any range. What changes is how many inches that represents. This is why angular units are used for scope adjustment and inches are not.
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