Angular units
MOA and Mil Conversion Chart
Quick answer
At 100 yards, 1 MOA is 1.047 inches and 1 mil is exactly 3.6 inches. One mil equals 3.43775 MOA at every distance, since both are fixed angles rather than lengths. The shorthand that treats 1 MOA as 1.000 inch at 100 yards is a convention, not a unit, and it is 4.5 percent small.
A minute of angle and a milliradian are both units for measuring an angle, not a length. A minute of angle is one sixtieth of one degree, which subtends 1.047197 inches at 100 yards by plain trigonometry: 2 x 3600 x tan(1/120 degree). A milliradian is one thousandth of a radian, which subtends exactly 3.6 inches at 100 yards by definition, with no trigonometry involved at all.
Both scale in direct proportion to range, and the ratio between them never changes: 1 mil is always 3.43775 MOA, whether you are holding at 100 yards or dialling at a mile. A third figure, shooter MOA or IPHY, treats 1 MOA as exactly 1.000 inch at 100 yards. That is a convention some shooters use for mental math, not a real unit, and it is 4.5 percent short of the true figure.
Every number on this page is exact arithmetic from those two definitions, not a measurement of any particular scope. Use it as the reference table for your range bag rather than recalculating it under time pressure.
What do 1 MOA and 1 mil subtend at every common distance?
The working
MOA inches at distance = 1.047197 x (yards / 100). Mil inches at distance = 3.6 x (yards / 100). Shooter MOA (IPHY) inches at distance = 1.000 x (yards / 100).
The MOA and mil figures are exact. The shooter MOA column is a convention included for comparison, and the gap column shows exactly what it costs you.
Read down for the distance you are working at. The gap column is how far short the shooter MOA convention falls of the true figure, and it grows in direct proportion to range.
At 500 yards, 1 MOA subtends 5.24 inches and 1 mil subtends 18 inches, while the shooter MOA convention gives 5.00 inches, a gap of 0.24 inches per minute at that distance.
Sourced figure
| Distance | 1 MOA (in) | 1 mil (in) | Shooter MOA / IPHY (in) | Gap, true MOA minus IPHY |
|---|---|---|---|---|
| 25 yd | 0.26 | 0.9 | 0.25 | 0.01 |
| 50 yd | 0.52 | 1.8 | 0.5 | 0.02 |
| 75 yd | 0.79 | 2.7 | 0.75 | 0.04 |
| 100 yd | 1.05 | 3.6 | 1.00 | 0.05 |
| 150 yd | 1.57 | 5.4 | 1.5 | 0.07 |
| 200 yd | 2.09 | 7.2 | 2.00 | 0.09 |
| 250 yd | 2.62 | 9.0 | 2.5 | 0.12 |
| 300 yd | 3.14 | 10.8 | 3.00 | 0.14 |
| 400 yd | 4.19 | 14.4 | 4.00 | 0.19 |
| 500 yd | 5.24 | 18.0 | 5.00 | 0.24 |
| 600 yd | 6.28 | 21.6 | 6.00 | 0.28 |
| 700 yd | 7.33 | 25.2 | 7.00 | 0.33 |
| 800 yd | 8.38 | 28.8 | 8.00 | 0.38 |
| 900 yd | 9.42 | 32.4 | 9.00 | 0.42 |
| 1,000 yd | 10.47 | 36.0 | 10.00 | 0.47 |
| 1,200 yd | 12.57 | 43.2 | 12.00 | 0.57 |
Every MOA and mil figure is exact from the two definitions. The shooter MOA column is convention rather than a unit, and on a 30 MOA come-up at 1,000 yards its 0.47 inch per minute gap compounds to roughly 14 inches, comfortably a clean miss on a torso sized target.
Full MOA to mil and mil to MOA conversion chart
Read the middle column for how many mils a given amount of MOA equals, and the right column for how many MOA a given amount of mils equals. Both directions use the same fixed ratio, 3.43775 MOA per mil, at every amount and every distance.
1 mil equals 3.43775 MOA and 1 MOA equals 0.29089 mil, a fixed ratio that applies at any amount and any distance because both units measure the same kind of thing, an angle.
Sourced figure
| Amount | This many MOA equals this many mil | This many mil equals this many MOA |
|---|---|---|
| 0.1 | 0.029 | 0.344 |
| 0.125 | 0.036 | 0.430 |
| 0.25 | 0.073 | 0.859 |
| 0.5 | 0.145 | 1.719 |
| 0.75 | 0.218 | 2.578 |
| 1 | 0.291 | 3.438 |
| 1.5 | 0.436 | 5.157 |
| 2 | 0.582 | 6.875 |
| 3 | 0.873 | 10.313 |
| 4 | 1.164 | 13.751 |
| 5 | 1.454 | 17.189 |
| 7 | 2.036 | 24.064 |
| 10 | 2.909 | 34.377 |
| 15 | 4.363 | 51.566 |
| 20 | 5.818 | 68.755 |
| 25 | 7.272 | 85.944 |
| 30 | 8.727 | 103.132 |
| 40 | 11.636 | 137.510 |
| 50 | 14.544 | 171.887 |
Multiply an MOA amount by 0.29089 to get mil, or multiply a mil amount by 3.43775 to get MOA. Both are exact, since the two units are related by a constant ratio at every distance.
How do the mil and MOA ranging constants work?
The working
Range in yards = target size in inches x 27.7778 / mils read. Range in yards = target size in inches x 95.4930 / MOA read. 27.7778 is 1000/36, and 95.4930 is 100/1.047197.
Both constants follow directly from the subtension definitions above. Reading one mil or one MOA on a known target size gives the range directly from the constant, with no other math required.
If you know how large something actually is, the mils or MOA it covers in your reticle tell you how far away it is. Here is what a target of each size reads at exactly 1 mil and exactly 1 MOA, which is the range in yards by definition of the constants above.
A 10 inch target that reads exactly 1 mil is 278 yards away, and the same target reading exactly 1 MOA is 955 yards away, since a mil covers more linear distance than an MOA at any given range.
Sourced figure
| Target size | Range at 1 mil reading | Range at 1 MOA reading |
|---|---|---|
| 3 in | 83.3 yd | 286.5 yd |
| 4 in | 111.1 yd | 382.0 yd |
| 6 in | 166.7 yd | 573.0 yd |
| 8 in | 222.2 yd | 763.9 yd |
| 10 in | 277.8 yd | 954.9 yd |
| 12 in | 333.3 yd | 1,145.9 yd |
| 18 in | 500.0 yd | 1,718.9 yd |
| 20 in | 555.6 yd | 1,909.9 yd |
| 24 in | 666.7 yd | 2,291.8 yd |
| 36 in | 1,000.0 yd | 3,437.7 yd |
For any other reading, divide these figures by the number of mils or MOA actually measured. A target reading 2 mils instead of 1 is at half the range shown in the mil column.
Why the shooter MOA shorthand survives, and when it stops being safe
Treating a minute of angle as exactly one inch at 100 yards is wrong by 4.5 percent, and it is a defensible simplification at short range purely because 4.5 percent of a small number is smaller than a group. The crossover is not a matter of taste: it is wherever that 4.5 percent of your come-up becomes larger than the target you are shooting at. Inside 200 yards it almost never matters. Past 600 yards it is one of the larger avoidable errors in the whole shot, and it compounds with every additional minute you dial.
Mil has no equivalent shorthand in wide use, because 3.6 inches at 100 yards is already round enough that nobody bothers approximating it. See the exact figures for a specific distance on the MOA and mil breakdown at 500 yards or the breakdown at 1,000 yards, both computed from these same constants with target size ranging tables built in.
Sources
- Definition of a minute of angle, one sixtieth of one degree
- Definition of a milliradian, one thousandth of a radian
Frequently asked questions
How many inches is 1 MOA at 100 yards?
1.047 inches, from the exact trigonometry of one sixtieth of a degree: 2 x 3600 x tan(1/120 degree). Many shooters round this to 1.000 inch, a convention called shooter MOA or inches per hundred yards, which is 4.5 percent short of the true figure and grows into a real error past a few hundred yards.
How many inches is 1 mil at 100 yards?
Exactly 3.6 inches, by definition, since a milliradian is one thousandth of a radian and 100 yards is 3,600 inches. There is no rounding and no trigonometry in that figure, which is also why 3.6 is the constant mil turrets and mil reticles are built around.
How many MOA is 1 mil?
3.43775 MOA, at every distance, because both units measure the same angle and their ratio is fixed. To convert an amount of mils to MOA, multiply by 3.43775. To convert MOA to mils, multiply by 0.29089. Neither figure changes with range, magnification or tube diameter.
What is shooter MOA or IPHY, and why is it different from true MOA?
Shooter MOA, or inches per hundred yards, treats 1 MOA as exactly 1.000 inch at 100 yards instead of the true 1.047 inches. It is a rounding convention for faster mental math, 4.5 percent short of the real figure. It is harmless at short range and costs roughly 14 inches on a 30 MOA come-up at 1,000 yards.
What is the mil ranging formula?
Range in yards equals the target size in inches, times 27.7778, divided by the number of mils the target covers in your reticle. The constant 27.7778 is 1000 divided by 36, and it follows directly from a milliradian covering one thousandth of the range at any distance.
Should I buy a scope in MOA or mil?
Neither unit is more accurate, since they are two ways of measuring the same angle. The only real decision is matching your reticle to your turrets, so a hold read off the glass is already the number you dial. See the full breakdown on MOA against mil for which one fits your existing gear and habits.
Researched, not professional advice. This page is compiled from published manufacturer specifications, published optical and ballistic formulas, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are shooter convention rather than sourced numbers, and they are labelled that way wherever they appear. Ballistic figures come from a point mass model using the ballistic coefficient the maker publishes, so treat them as a starting point and confirm them on paper at a measured distance. Confirm your firearm is unloaded with the action open before you mount, level, torque or bore sight anything. Verify a zero only on a supervised range or a safe, legal backstop, know what lies beyond your target, and follow the law where you hunt and shoot, including rules on land access and permitted cartridges.