I haven’t had too much time to knit lately, but I’ve been doing a little bit of test sock knitting, trying to find out what dimensions work best for my feet.
I find that most of the directions I can find on fitting socks are not quite detailed enough for my brain. For example, even just in how to measure your foot. When you measure the circumference of your foot, do you do it while standing, or while your foot is at rest? There’s quite a difference. And when you measure the length of your foot, do you measure the “footprint” (from the tip of your toe to where your heel starts to lift from the ground), or the total length of your foot to the farthest point on the back of your heel (for example, stand with your heel against a wall and measure from the wall to the tip of your toes).
And what about negative ease? I like my socks on the snug side so they don’t bunch up in my shoes. Most tips I’ve seen say to calculate the number of stitches as your foot circumference multiplied by your number of stitches per inch, and then reduce the total by 10-15%. (Other instructions I’ve seen have been to go by the ankle measurement instead of the foot circumference, sometimes subtracting an inch, sometimes not.) But what about the length? That seems to be where I have the most trouble. Mostly I just see instructions to knit until the length is about 2″ short of the total desired length. Is that assuming that the length of the sock toe will be around 1 1/2″, so that the sock length will be about 1/2″ less than your foot measurement? And when measuring your sock to see if it’s long enough, do you measure it from your needles to the very farthest point of the heel, or just to the heel turn? (Maybe that depends on how you measured your foot in the first place).
Do you adjust your sizes based on the fiber, depending on whether you expect it to stretch out when worn, or perhaps shrink when washed?
I figure that for my own socks, once I figure out a basic formula that works for a particular yarn gauge, I can modify patterns as needed for the right fit. But if I knit for someone else, especially if I don’t have measurements and am working from foot size charts (such as the nice one in “Sensational Knitted Socks”), these questions become more important. I suppose that as I get more experienced with socks, I’ll come up with some answers. But if you’ve got any helpful hints, or special tips that have worked for you, I’d love to hear them.
If I have the person measure his/her foot, I ask them to do it while they are standing. Then I subtract about 10% for negative ease.
I knit my socks with no negative ease length wise (and I measure the total length not the foot print), but I do use ~10% negative ease around the foot. This results in a nicely snug sock inside my shoes still.