The following is a rough guide for sizing yourself for a Blundstone: For men, subtract about 1 full size from your North American size to find your Blundstone size. IE) US Size 11 is about a Size 10 in a Blundstone. For women, subtract about 2.5 sizes from your North American size to find your Blundstone size. IE) US Size 8 is about a Siz