Simply put, MRAD is a measurement unit of angle that tells us how change in optics take effect in different distances. In other words, if we move the sight by 1 unit, how much does the target move in 100 meters.
MRAD is very similar to MOA in its function, but the measurement units are in metric system:
- for 1 MOA the target moves 1 inch in 100 yards.
- for 1 MRAD the target moves 10cm in 100 meters.
MRAD in simple language
MRAD measurement tells us how big a change in the scope setting is going to be in different distances.
Compared to MOA measurement used mainly in US (due to imperial system), MRAD is measurement that can be much more easy to be used in the rest of the world.at larger distances.
In US you may find MRAD more handy only because it is faster for adjustment. Generally MRAD scopes are adjusted by 1/10 of MRAD. Therefore in 100 meters one click means movement of 1cm. That can bet translated to cca 0.36 inches per 100 yards.
On MOA scopes the adjustment goes by 1/4 of the MOA. That means that by 1 click we adjust the target by 0.25 inches. MOA scopes are therefore more precise for adjustments compared to MRAD scopes.
MRAD technical details
MRAD stands for miliridian and it comes from the standard metric system of measurement. Since we dont use metric system in US, MOA is more convenient to use for us.
Miliradian (MRAD) is a measurement of angle same as minutes of angle (MOA). And while for MOA there are 21 600 minutes in a circle (360 degrees, each with 60 minutes), for MRAD there are 6 280 miliraridans in a circle. Why? Because the circle is devided into 6.28 sections per 57.3 degrees. In other words, there 6.28 radians in a circle. Since each radian has 1000 miliradians, there are altogether 6 280 miliradians in a circle.