The other poster's advice is correct. I am an 8D on the Brannock. I have 2030s in 7.5 (thicker socks) and also in 7 (thin socks). So I went down a full size for the 2030 for use with thin socks. The most common advice is to go down 1/2 size from your Brannock or US size. So to be safe, you should go with a 7 in the 2030 last. If you've got medium to thinner feet, or you're on the smaller side of 7.5D, then you could go with a 6.5.