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.
Updated · Recently improved tools
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.
🔒 This tool runs entirely in your browser. Nothing you enter is uploaded, logged, or stored.