Waist width, rocker and turn radius in plain English
Three numbers on every spec sheet tell you most of what a ski will feel like. Here’s how to read them.
Every ski lists three widths like 128 / 92 / 114, a length and a turn radius. Once you know what they mean, a spec sheet tells you a lot before you ever click in.
Waist width: float or quickness
The middle number is the waist, the width under your boot in millimeters. Narrow skis switch edges fast and grip hard snow. Wide skis float in soft snow but feel slower edge to edge.
- Under about 90 mm: groomers / on-piste skiing, and most beginners.
- About 90 to 115 mm: all-mountain / freeride skis that handle the whole mountain.
- Over about 115 mm: powder days.
Tip and tail: the hourglass
The first and last numbers are the tip and tail widths. The bigger the difference between them and the waist, the deeper the hourglass shape and the more the ski wants to turn. A tail almost as wide as the tip, as on a twin tip, makes the ski easy to ride backward and quick to pivot. A narrower tail finishes turns cleanly and holds on firm snow.
Rocker and camber: grip or ease
Look at a ski from the side. Camber is the gentle upward arch underfoot. It gives grip and rebound on firm snow. Rocker is where the tip or tail curves up early, like a banana. It helps the ski float in powder and start turns easily. Most all-mountain skis combine both: camber underfoot with rocker at the tip and tail.
Turn radius: snappy or calm
The turn radius comes from the sidecut, the hourglass shape you see from above. It is the size of the circle the ski would carve on edge, in meters. Under about 15 m makes quick, short turns. Around 16 to 20 m suits all-mountain skiing. Over 20 m feels calm and stable at speed.