To determine the range to a target without a laser rangefinder, the sniper may use the mil dot reticle on a scope to accurately find the range. Mil dots are used like a slide rule to measure the height of a target, and if the height is known, the range can be as well. The height of the target (in yards) ×1000, divided by the height of the target (in mils), gives the range in yards. This is only in general, however, as both scope magnification (7×, 40×) and mil dot spacing change. The USMC standard is that 1 mil (that is, 1 milliradian) equals 3.438 MOA (minute of arc, or, equivalently, minute of angle), while the US Army standard is 3.6 MOA, chosen so as to give a diameter of 1 yard at a distance of 1,000 yards (or equivalently, a diameter of 1 meter at a range of 1 kilometer.) Many commercial manufacturers use 3.5, splitting the difference, since it is easier to work with.