Board Thread:Wiki discussion/@comment-4881935-20130327060139/@comment-3974211-20130408020332

The5lacker wrote: 4. Diameter is merely 2 * Radius, and therefore can be easily found by simply doubling the radius, rather than listing only Diameter with requires one to divide a number by 2, which is harder to do off of the top of someone's head.

Not true. The radius of an ability is calculated from the exterior of a champion. Therefore, the diameter of an ability is larger than twice the radius.

Diameter is preferred when it is fixed and unchangable. Radius/range is preferred when the diameter is variable. Radius in impractical when there is no focal point for the center - such as any ground-targeted area of effect. Players want to know how wide it is - not how wide half of it is. If they want to know it's radius.