Changing an existing pattern to fit a different sized foot
Now that everyone understands how the different parts of a sock relate to one another it will be easier to adapt an existing pattern. Most sock patterns are made for women's feet. To be more precise, most sock patterns are made for what's called "average women's feet." Average US shoe size is about a 7.5 or 8 for women, so if you're bigger or smaller (or just wider or narrower), you might have to adapt a pattern. If you're knitting socks for a man or a child you might also have to adapt the pattern.
Before you can adapt a pattern however, you will need to figure out the stitch repeat used in that pattern. If you're adapting a stockinette stitch or 2/2 rib pattern, you can just follow the directions for the basic custom sock pattern given in the first part of this tutorial. If you are using a more complex pattern you'll have to know your stitch repeat before you can start changing sizes.
A stitch repeat is the number of stitches that any pattern has before it starts over again (repeats). For instance K2, P2 is a 4 stitch repeat - you work 4 stitches before you start again at the K2. K1, P2, K1 is also a 4 stitch repeat. K1, YO, Slip one, K2tog, pass slipped stitch over, YO, K1 is a 5 stitch repeat. P1, 2/2 Cable Right, P1 is a 6 stitch repeat. There is no limit to the number of stitches a repeat can have, but when you're changing sock sizes, the smaller the repeat, the easier it is to adapt. (I'll give suggestions below for working with bigger repeats, but make your first pattern adaptation easy on yourself by working with a smaller repeat.)
Once you've figured out how many stitches are in each repeat, you will use this to adjust your primary number ("A" in our sample pattern). For instance, if I need 88 stitches to fit a sock to Mickael's foot and the stitch pattern I'm using has a 4 stitch repeat, I can just plug the numbers straight into my sample pattern and start knitting. 4 goes into 88 evenly (22 times) so I work the sock on 88 stitches, the heel over 44 stitches, work toe decreases every other round until I have 44 stitches, and every round until I have 24 or 20 stitches (22 isn't divisible by 4 so I have to juggle this last number a bit). On the other hand, if I'm making a sock with a 6 stitch repeat for Mickael, I need to change my "A" number. 6 doesn't go into 88 evenly, but it does go into 90. In this case I'd cast on 90 stitches, but I'd have to juggle my heel/instep stitches a little. Theoretically I should have a 45 stitch heel flap and use 45 stitches for the instep, but then I would only have 7 full repeats plus 3 extra stitches on the instep. I need full repeats* for the instep so I should either use 48 stitches for the heel flap and save the other 42 for the instep OR I could use 42 stitches for the heel flap and save 48 for the instep. I'd make that decision based on how wide or narrow Mickael's heel is. I'd have to juggle the toe decreases in a similar manner (either 90 dec to 48 dec to 24 OR 90 dec to 42 dec to 20) and I'd use the shape of his foot to make that decision - the first set of numbers will be more comfortable for widely spaced toes while the second set would fit longer, more close together toes because there would be more rounds. At this point, since we understand the basic relationship between the parts of the socks, it's easy to juggle numbers a bit so that we can fit the sock around a certain stitch pattern as well as a particular foot shape.
There's one other thing to take into account when you're adjusting patterns and this also affects the instep/heel flap stitch division. Some patterns aren't balanced in a single repeat and need an extra stitch or two be balanced. For instance, if you knit a leg in K2, P2 rib and knit another leg in K1, P2, K1, your legs will look the same. When you divide for the instep/heel flap though, the first leg will have a K2 on one side of the instep and a P2 on the other side and be unbalanced. The second leg will give you a K1 on each side of the instep and will be balanced. On a simple pattern like a K2, P2, in order to balance the instep you can easily work one extra knit stitch before turning for the heel flap and turn your stitch pattern into a K1, P2, K1. Then you wouldn't have to adjust numbers. On a more complex pattern, you might need to add a few stitches to the instep in order to balance it. If my stitch repeat is P1, K1, YO, Sl 1, K2tog, psso, YO, K1 (a six stitch repeat), I would use a multiple of 6 plus 1 for the instep stitches. Do you see the P1 at the beginning of my repeat? There isn't one at the end of the repeat so there's only a single purl stitch between repeats. By putting one more purl stitch at the end of the instep stitches (not at the end of every repeat), I've balanced my instep and have a better looking sock. Let's use Mickael's imaginary 90 stitch sock for an example (although I think the stitch pattern I've made up might be a little lacy for him). I've decided to work the heel flap over 48 stitches and the instep over 42, but now I'm going to need 43 stitches for the instep in order to balance the stitch pattern. This leaves me 47 stitches for the heel flap. Taking one stitch away from the planned heel flap isn't a big deal, but if it bothers you, or if you take out more than one stitch, you could always increase evenly over the first row of heel flap (the WS purl row). When you get to the gussets, just decrease back down to whatever your "A" number is.
If you are trying to adapt a pattern with a large repeat and it's just not working with your yarn gauge and foot size, try looking for places you can expand or decrease the actual repeat count. For instance, if you're adapting a cabled sock pattern and the cable is 24 stitches wide and you need your sock to be 64 stitches around, you can work two repeats, but you'll have 16 stitches left over. The easy way to adjust this would be to add two "filler" stitch panels of 8 stitches each between the two cable repeats. Filler stitches can be anything from ribbing to seed stitch, a small cable or a simple lace pattern - anything small that can be adjusted to fit the space you need to fill. Occasionally you will find a stitch pattern that just won't adjust to a different size very well. Your option here is to find a different yarn and needle combination that will give you a different gauge or find another stitch pattern that gives you a similar look that's easier to adjust.
I've adapted the sample pattern from the first part of this exercise to include adjustments for stitch repeats.
- Make a gauge swatch and figure out how many stitches per inch you are getting. Use any yarn weight and needles of appropriate size. Write down your gauge here:_____Stitches per inch.
- Measure your foot (or the foot of the person who's getting these socks) around the ball of the foot (or the widest part). Foot measurement:______ Inches around.
- Multiply the number of stitches you are getting per inch by your foot measurement. Write that down here:_____.
- Now, there is an option at this point regarding ease. Some people like their socks to fit snugly - if that's you, multiply the number you just got by 90% or 0.90. If you don't want your socks to fit snugly, don't change anything. Write down your new number here or the same number from Step 3 depending on the choices you made:_____.
- You'll need to know how many stitches are in each pattern repeat ______. If your number from Step 4 is divisible by your stitch repeat number, you won't need to change anything. If it's not, you'll need to adjust the number from Step 4 either up or down to make it divisible by your stitch repeat. For instance, if your repeat is 6 and you have 88 stitches in Step 4, you can round up to 90 or down to 84 stitches. Write down your new number that's divisible by your repeat here:_____.
- The number in Step 5 is your primary number or "A." This is the number that all your other numbers will be related to. Anytime I refer to this number, I will call it "A" with the quotes and everything. If I say "1/2 of A", you'll need to divide "A" by 2. If I say "1/4 of A", you'll need to divide "A" by 4. Don't worry, it's pretty easy.
- Cast on "A" stitches and divide them evenly over 4 DPN's. (I know, after all that math you forgot we were even knitting socks, didn't you?)
- Join without twisting stitches and work the leg of your sock in your desired stitch pattern. You might have a cuff, you might not - use the pattern you are adapting and work the leg until it is the desired length before the heel flap.
- Now we'll start the heel flap. The heel flap will be worked over "1/2 of A" stitches. Here is the first place we might have to juggle our stitch count. Also remember that you might need to balance the stitch pattern on your instep stitches. Plan for this now (chart it out if it helps you to see it better). The other stitches not used in the heel flap will be held for the instep. Turn your work and work a WS row as follows: Slip 1, P remaining heel flap stitches. If you need to increase any stitches in the heel flap, work those increases evenly across this first row. Turn your work and *Slip 1, Knit 1, rep from * to end of heel flap stitches. You've now worked 2 rows of the heel flap. Continue working these two rows until you've worked "1/2 of A" rows total in the heel flap, ending with a RS row. Make sure you end with a RS row here even if that means you work one more or one less than "1/2 of A" rows - you want to work an even number of rows in the heel flap for the rest of the directions to work.
- Start the heel turn as follows. (WS row) Slip 1, P 1/2 of the heel flap stitches (the total number of stitches on your right needle after this step will be 1/2 of the heel flap stitches plus 1), P2tog, P1, turn. Next row (RS) Slip 1, K3, SSK, K1, turn.
- Now that the heel turn is begun, you'll complete it as follows. WS rows: Turn, Sl 1, P to 1 stitch before the gap (there's a little gap between the stitches you've already worked in the heel turn and those waiting to be worked), end P2tog, P1. RS Rows: Turn, Sl 1, K to 1 stitch before the gap, end SSK, K1. Continue repeating these two rows until you've picked up and worked all the stitches from the heel flap.
- Divide the heel stitches over 2 needles. With the needle on the left (the one with the working yarn on it, pick up and knit stitches along the side of the heel flap, down to the joint between heel flap and instep stitches. It's more important to pick up enough stitches so you don't have holes here than it is to pick up a specific number of stitches. Work across the instep stitches in your stitch pattern, working any additional balancing stitches. Then pick up stitches along the other side of the heel flap. Try to get the same number of stitches you did the first time, but if you get one more or one less, you can just work an extra decrease on the side with the extra stitch later. Extra decreases aren't noticeable, holes are, so pick up what you need to not leave holes. Knit across the heel stitches and then back across the first gusset stitches. You will have completed this round when the working yarn is between the gusset stitches on the right and the first needle of instep stitches on the left. (New rounds begin with the instep stitches.)
- Work one round even. Keep instep stitches in pattern and keep heel and gusset stitches in stockinette.
- Decrease round - Work instep stitches in pattern. Heel/gusset stitches should be worked as K1, SSK, K to last 3 stitches of round, end K2tog, K1.
- Work the previous two rounds (decreasing every other round) until your total stitch count is "A" again. If you have an extra stitch on one side or the other, on the final decrease round, only decrease on that one side to get your stitch count back to "A." At this point you might not have the same number of stitches on each needle, particularly if you divided the heel flap and instep stitches unevenly. Before you begin the toe decreases, it's crucial that you have the same number of stitches on each needle and that the instep stitches are centered over the first two needles of the round. If you can't just shift stitches around to do this, consider working a couple of rounds of stockinette before starting toe decreases or work an additional decrease on the last round before toe decreases. (I've done this when I have an odd number of stitches on my instep. For example, if I have 33 stitches on the instep and 32 stitches on the sole, I'll decrease one extra stitch somewhere in the pattern on my last round of the pattern, then make sure I've got 16 stitches on each needle and the instep is centered over the first and second needles of the round before starting toe decreases.)
- Work even until the foot of the sock reaches the point between your big toe and it's neighbor (where a flip flop would go).
- Begin Toe Decreases. (If you're working the top of the foot in rib, you'll switch to stockinette for the toe.) Decrease Round: K1, SSK, K to last 3 stitches of instep, K2tog, K1, (sole of sock) K1, SSK, knit to last 3 stitches of sole, K2tog, K1. You've just decreased 4 stitches in this round.
- Work one round even.
- Continue alternating the Decrease Round with an even round until you have "1/2 of A" stitches left.
- Work the Decrease Round only until you have "1/4 of A" stitches left (you might need to tweak this number a bit if "1/4 of A" isn't divisible by 4.) Get as close as you can to "1/4 of A" in this type of situation.
- Kitchener Stitch the toe closed.
Again, any comments on what you'd like to see added to this tutorial would be great. I will include chart examples of stitch patterns and show how to balance them in the pdf but I didn't have time to work them all up for the blog post. Let me know if there's anything else sock related that you'd like me to cover and I'll see what I can do!