Sizing your skis

I was trying to find some info on sizing my daughter's skis. Here's some interesting sizing advice from an article at ehow.com, January 2012:

See the problem with the formula? Multiply your height by 2.6 and then divide by 25 to find your ski length. Or, just divide your height by 10 essentially. I'm 6'1", or 73 inches, so my skis should be 7 inches long. That's nice, I can fit them in my pocket. No more struggling to get them into the car. Unfortunately, my ski boots are twice that length, so I'm not sure I'm going to attach the bindings.

I found the original article at Ski Post, and they write:

"For Traditional length classical skis (Your height in inches) x 2.6 + 15 inches = approximate ski length in cm."

There's still conversion and unit issues here. Better:

(Your height in inches) x 2.54 cm/in + 15 cm = approximate ski lenghth.

Or how about just: Your height + four to twelve inches?