Typically, the Zipfit inner boot size is the same number as the shell’s factory liner. To be sure use a metal measuring tape with metric markings, push it down to the toe end of the shell and bend the tape into the heel pocket. Note the internal measurement in centimeters or millimeters. If example the measurement is 266mm or 26.6cm your liner is a size 26.5.

Sven’s Sizing notes

The issue of SIZING has always been a perplexing problem. It is much better today, after a campaign I started forty years ago when I was accused of exaggerating the issue. In Berlin, circa 1973, I presented a Standardized sizing system at the first ISO/DIN Ski Equipment Safety meeting. It was simply the Japanese “metric” sizing and surprisingly everyone agreed, yet they ended up doing whatever suited them. Now the binding-adjustment sole length has been added as a vague sizing reference. To make the matter even more confusing, women’s boot sizing is inconsistent at best and should always be stoichastically measured.

Why can the boot manufacturers state the “shell’s” own internal equivalent foot size?
Maybe because — they also refer to the sole length as the sizing reference?

Anyway, let’s just use some simple shell measurements to help get you, the skier, into the proper Zipfit liner.


What I have recommended in the past is to use the measuring tape inside the shell. To do this, extend the tape into the boot as far as it can go into the toebox. Then by using your hand to push the tape deep into the heel cavity, it will curve up the back giving an internal shell length.

BLUE lines show the middle of the tape bend and the internal shell size of 285 mm. This is also the external Zipfit length, allowing for materials.
WHITE lines show the Zipfit internal size of 275 mm, and the actual foot size within the Zipfit….