A daily blogger I've been following quite a while, because she's a heck of a seamstress (and now a knitter too), Mermaids, asked:
"i am in the same boat in terms of hoping i have enough a yarn to finish a pair of socks. with fabric, it is so easy to tell if you have enough. how do you do that with yarn?!?!"
Peeps, this is the first time ever that someone has asked me a knitting related question on this blog. How can I refuse to answer? What type of person would I be? Would anyone ever ask me a question again about knitting? Let's go through how you can know.
Now, as the wise Ms. Knitpicky mentioned in her own comment, the ideal way to handle this is pre knitting anything. And considering she knits roughly a mile of yarn a month, she should know! You can, if you are worried, split your yarn into two equal yardage balls prior to ever knitting a darned stitch. Just wind those center pull balls and weigh them. Do they weigh the same? If so, get knitting!
I, normally, never run into this problem because I usually knit the same pattern for the same size feet (my own) all the time. Thus, I know exactly how much yardage I need to do that standard pattern. I guesstimate based on that yardage for other people's feet and other patterns. Sometimes, I guesstimate wrong. For instance, when I knit Helen's socks, I was only partially sure that I'd need two skeins of Lorna's Laces because when I knit myself anklets, I use less than one full skein. It turns out that when the person you're knitting a pair of knee high socks for size ten feet, you need to go the extra distance with your yarn purchase. Alternatively, I was absolutely sure that my purchase of yarn (roughly 430 yards or so) for Paul's normal height socks would leave me wanting more since he wears extra wide socks. I had enough left over yarn to make my baby a pair of tiny booties that matched! So, guesstimating only works well if you're knitting for yourself and for a pattern that's roughly the same height as you usually wear.
But, wait, you're saying! I knit a darned sock already! I need to know if I have enough yarn to match this first sock. Well, remember that scale that Ms. Knitpicky would have pulled out prior to even knitting? Yeah, go get it. Weigh your first sock. How much does it weigh? Note that! (I use my husband's kitchen scale for this task since it can tare out weights and it's really accurate.) Now, weigh your remaining yarn. If you have the same number or a heavier weight, you're good. If not, you might want to shorten your first sock now.
Hmm, I didn't include any pictures in this post. Nathan finds himself displeased with this post for that reason.