If you would like to make sure the girth of the foot is going to be accommodated, check against the table below. Don't know your size and width yet? Then follow the instructions here.
If possible measure the feet when the swelling is greatest which is usually late afternoon or early evening. With a flexible tape measure around the arch of the foot. If you don't have a flexible tape, use a piece of string or similar and then measure that.
Below is a complete chart of all of our measurements for sizes, widths and girth ranges combined into one big table.