I agree with the other posters. Measure your order before washing. I will go one step further: when you purchase a kit, open it immediately and check that ALL the fabric has been included, and that each piece is at least as large as stated in the kit contents list. Also check that the pattern has been included. Ask me why I now do this.
On the other hand, several years ago, I purchased a kit from the clearance section of an LQS. It was on clearance because one piece in the kit had been mis-measured. I got a beautiful $175 kit at 75% off and it was short only 1/2 yard of fabric which I was able to substitute. Pretty good deal in my eyes!