Presumably this is one piece of fabric rather than two sewn together to get the width.

You will need to check that the two halves will fit together - preferably before cutting it.

Some cloths are not quite evenly woven, which is not a problem until you want to put the two halves together and have a perfect match.

Assuming this is a tartan material then it should be easy to lay the edges alongside and see how they match. You might need to trim the edge where they join so as to get the sett to match

Depending on how wide the fabric is you could get two pieces wide enough for the depth of the kilt and a piece from the centre to make the waist binding - to cover the cut edge, and some belt loops.

I have been making my kilts in a simple way, and reducing them is size as I have been losing weight. Some have been remade three, or even four times.

I put in the pleats, first pinning and then sewing them in place at the top edge. I take a strip of the fabric and bind the top edge, add belt loops, but I just press in the pleats as I get them correctly folded, and then press in the shaping from waist to hip once it is together, then wear it with a belt to keep it closed.

When it needs to be made smaller it is easy to remove the belt loops and binding, then release the pleats and either fold them closer together, or open out the fabric, wash it and hang it to dry, then iron the whole thing flat so as to have no folds from the previous incarnation to spoil the new one - and they will if you don't really flatten them out.

I have hand sewn more and more of my kilts as I find it is easier to make changes and it is more gentle on the fabrics I use than machine sewing would be.

When pressing the edges of the pleats I use a piece of thick cardboard, from the centre of a bolt of cloth, so I can place the fold on it and isolate it from the rest of the kilt. This seems to work very well.