Exact Sizes


Size of 1 MOA

1 MOA

How to calculate the size of 1 MOA at range X.

The circumference of a circle can be calculated using these formulas:

diameter * PI = circumference
(2 * Radius) * PI = Circumference

So let us consider a circle in which you are the center and the radius is the range to the target. In this example, let's say the range is 400 yards (which is 14 400 inches). The circumference is:

(2 * 14 400) * PI = 90477.87 inches

Since 1 MOA is 1/60th of 1°, 1 MOA at 400 yards will be the circumference divided by 360 (number of degrees per circle), divided by 60 (number of minutes per degree). Therefore:

90477.87 / 360 / 60 = 4.19 inches

Size of 1 mil

How to calculate the size of 1 mil at range X.

Use the same circle formulas. So for a range of 400 yards, the circumference is:

(2 * 14 400) * PI = 90477.87 inches

Since 1 mil is 1/6400th of a circle, divide the circumference by 6400. Therefore:

90477.87 / 6400 = 14.14 inches

Calculated values

Here are the calculated values for ranges 100 to 1000 yards:

Range1 MOA (inches)1 mil (inches)
100 1.05 3.53
200 2.09 7.07
300 3.14 10.6
400 4.19 14.14
500 5.24 17.67
600 6.28 21.21
700 7.33 24.74
800 8.38 28.27
900 9.42 31.81
100010.4734.34

To simplify calculations, used MOA sizes are 1,2,3,4,... Mil sizes are 3.5, 7, 10.5, ...


Formulas in this page


diameter * PI = circumference
(2 * Radius) * PI = Circumference