I'm using a pattern from an Internet site based in the UK. I went to a local yarn store and they told me that Heartland yarn (Lion Brand) was equivalent to the Aran weight yarn called for in the pattern. However, when I cast on 18 stitches on #6 (equivalent to 4mm needles called for in the pattern) needles, it didn't measure 4 inches, which it was supposed to. I tried #8 needles, but still didn't get 4 inches. I think the yarn weight is probably incorrect, but I really don't know because this is a very knowledgeable yarn store. Thanks in advance for your help.