Sure, there is around an inch and a half difference in the waist between the size 1 and size 3. For the seat, about an inch. I do want to note that we offer free exchanges, so if you are interested in moving to a different size, you can visit this page: http://www.wrglr.co/1seWSNf
and complete the form. With exchanges, we cover the cost of shipping the garment back and the cost of shipping the new garment to you. If you have other questions or we can be of further assistance, please don't hesitate to reach out to us directly at 888-784-8571.