The difference between the US and UK sizes is about 1/2 size. The B width is a narrow width boot, D Width is a medium or standard width boot, and E or EE is a wide width boot. Please note if you never worn western boots before that to order your regular US street shoe size. Western boots are made a bit larger than regular street shoes and are meant to be broken in for perfect fit. With the US to UK difference the make up is a wash in size. You should be fine with your regular shoe size in these boots.