A most warm welcome to X Marks; I can hardly imagine a better way to introduce yourself than trying to make a X-Kilt!

As Raibeart mentioned, the Do It Yourself (DIY) Form would probably have gotten you a quicker response, but that is OK. We will still take care of you.

OK, so what is this mysterious measurement all about? This measurement is to help you make sure that your overall math and measurements are about right. The goal here is to make sure that at the bottom of the fell (where you have done the bar tacks), the kilt will fit around your bum. So, with this in mind, you can imagine that you want to measure starting at the open end of the over apron all the way to where the over apron meets up with the last box pleat (the first one next to the under apron). To put it another way, this measurement is the measurement of the width of all of the pleats + the width of the over apron.

With the above in mind, you should now be able to figure out what is right vs. left.

'Right' would be your right as you are wearing the kilt. Yes?

As for even or odd number of pleats, as long as you are doing the box pleat style, it does not matter. If you ever try the Reverse Kingussie (RevK) style then you must have an even number of pleats.

Enjoy!

Make sure to post a picture or two of the final product.