My regular socks take more than half, but not all, of a 100 g ball of worsted-weight yarn. The leftover yarn is enough to do "something" with but I wasn't sure what. So, since I wanted short socks to wear in summer when bicycling, I decided to see just how far the leftover yarn from one sock would go toward making another sock. And with a bit of thinking, came up with a design I thought might work: a rolled top, then a short bit of ribbing (about 3/4 inch) then a short bit of stockinette before making the heel as usual. Not all the "regular" socks are exactly the same, since I've been refining their design bit by bit...so not all the leftover yarn is exactly the same length However, I now know that the leftover will make over half of a short stock. I finished all the "first yarn" on both socks--not quite the same length, but close enough. I've put them on, with my feet through the needles, and like the fit, so now to use up more leftover yarn and finish them.