There is often confusion between the RoH of a blade and the profile (or rocker). This confusion is understood because both use the radius of a circle as their measurment. When referring to the RoH (the depth of the groove on the bottom of your skate blade), the measurement is in inches (or centimeters). When referring to the profile of the skate blade, the measurement is in feet.
The radius as it relates to a custom profile, imagines the length of the skate blade (from heel to toe) as part of a larger circle. The most common sizes are a 9 foot radius, an 11 foot radius and a 13 foot radius, although they are not limited to just these. With a smaller radius (9 ft), less of the skate blade comes in contact with the ice. With a larger radius (13 ft), more of the skate blade comes in contact with the ice. Both have their pros and cons and that is why it is important for each individual player to try. Generally speaking a smaller radius is better for agility and maneuverability and a larger radius is better for speed, so those might be good things to keep in mind when you're deciding where to begin with your experiment.