This is a very cool converter that I stumbled across recently. http://www.thedietdiary.com/knittingfiend/tools/YardageConversion.html
I wish I’d known about it sooner. I often re-knit items with different weight yarn (especially accessories). Usually it’s because I buy yarn not knowing what it is going to be when I get around to knitting it. So I often have odd balls left over that I like to use up knitting hats or gloves. This question used to come up as well when I worked in my LYS. Many knitters aren’t afraid to re-gauge an existing pattern often just knitting a different size to accommodate the differing stitch counts. You can often change to a heavier or lighter weight yarn than the original pattern called for with no negative consequences.
You can find the free glove pattern here http://www.berroco.com/exclusives/glover/glover.html