Quad Plate Sizing Chart
The quad plate sizing is based on what most FreeStyle Skaters would use. This is a longer skate Frame, or longer wheel base with the front axle just slightly in front of the ball of the foot, so the skaters would have a larger landing platform and not go on the toe stop as easy when landing jumps. This sizing is also used for most Quad Speed Skaters, Jam Skaters, Roller Derby, and some Recreational Skaters.
For Dance Skating and Figure Skating the desire would be to have the front axle directly under the ball of the foot. This may also prove to be the best way for Roller Derby Girls to size their Frames, as Maneuverability is very important in this sport. This may mean that on some boots the Frame size would be smaller that shown on the chart.
For Figure Loop Skating most of the top level coaches encourage their students to have a slightly shorter wheel base, if using two pairs of skates for figures. This would usually mean one half to one whole size shorter than that used for the large circles. The shorter wheel base is said to allow better control in the loop portion of the circle.
For Quad Roller Ball Hockey the normal is to use a Frame that is about two whole sizes shorter than the chart will show. This is so they can get to their Toe Stops faster for quick starts and stops.
The Chart Itself
The Chart is a compilation of many other charts from many sources, including some of the manufacturers mentioned, and this Chart has been used successfully for several years. The Information is not guaranteed to be correct, and as you can see personal preference has a lot to do with the selection of a Frame size.