Looking for advice on ordering tartan

[The Wizard of BC]

In general there are four factors which determine how much fabric a kilt will need.

1) The circumference of your hips.

The larger you are, the more fabric needed to go around you. In general we say that under 45 inches = 4 yards of double-width fabric. Over Between 45 and 50 inches = 4.5 yards of double-width fabric. Greater than 50 inches = 5 yards of double-width fabric.

2) The way that you plan to fold the fabric into pleats.

We call a knife pleated kilt with pleat reveals of between 5/8 inch and 3/4 inch an 8 yard kilt.
We call a knife pleated kilt with pleat reveals of greater than 1 inch a 5 yard kilt.
We call a box pleated kilt a 4 yard kilt.

3) The size of the Sett of the Tartan. (Which Tartan and the weight of the fabric you choose)

The larger the Sett = the more fabric each pleat requires.
The average Sett size is about between 6.5 inches and 7.25 inches.

4) How you want the Tartan pattern to display in the pleats.

If you are folding the fabric so the same element of the Tartan is down each pleat we call this "Display to Stripe". Each pleat will require one full Sett of fabric.
If you are folding the fabric so the entire Tartan is duplicated in the pleats we call this "Display to Sett". Each pleat will require one full Sett of fabric + one pleat extra.
So, Display to Sett requires slightly more fabric.

You have given us your hip circumference but we need the the other three things to know exactly how much fabric you will need.