My Sock Formula (I hope this makes sense as it never does when I try to explain it to people):
Lots depends on the gauge of yarn and the size needles that you choose to use. There is no magic to this, just decide what you want to use and then play around with the first few rows until you find a size that works. After you've done this a few times, you'll start to get it on the first try and you will look at yarn and say "Oh I need to use size 3 needles and cast on 48 stitches!"
With all of this, scale up and down depending on who your making your socks for!
I knit my socks on 3 needles but the stitches are divisible by 4 so you can use 4 if you prefer.
Also, DPN's for the win! I hate circs and I hate toe ups. But this of course will work with any needles you want to use, I won't judge.
Ok so here goes:
You must use a number of stitches divisable by 4, AND there must be an even number of stitches on each needle so here are your choices:
16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76..... 120 (if you are indeed big foot)
X = Total number of stitches
Y = X/2
Z = X/4
For adult socks and needles ranging between size 0-3 my stitches are usually between 48-72 depending on the gauge of the yarn.
The formula stays the same no matter how many stitches you start with.
For my example I will use 48 stitches
Total Stitches = X (48)
Needle #1: Y (24)
Needle #2: Z (12)
Needle #3: Z (12)
Knit in k1 p1 rib until the cuff is as long as you want it
(you can do k2 p2 rib if you prefer)
k3 p1 around until the leg is as long as you want it
***This is where the magic begins***
On needle #1 (and this is why we started with half of the stitches on one needle)
you will now work back and forth on this needle as you create the back of the heel (what ever they call that thing)
row 1: s1 k1 across BUT
(on the first slip stitch be sure to slip with the yarn in front as if to purl,
this will make your life easier later when you pick up stitches.)
row 2: s1 Purl across
(this time slip the stitch as if to knit, again making your life easier later)
Repeat these 2 rows times Z (12) times
(we started with X (48 stitches)
so we will do these 2 rows Z (12 times, which will be 24 rows,
and will leave 12 slip stitches on each side for picking up later!)
Turning the Heel:
on the next right side row: sl (as if to purl) then knit (Z-1) stitches across, k2, ssk, k1 turn
wrong side: s1 (as if to knit) k5, p2tog, p1 turn
right side: s1 (as if to purl) k until 1 stitch before the gap (you'll see it, trust me) ssk the stitch before the gap and the stitch after the gap, k1 turn
wrong side: s1 (as if it knit) purl until the gap (yes you will see it) p2tog p1 turn
REPEAT until you have no more gaps and all stitches have been knit.
Now, if you are using 3 needles, now's a good time to grab that 4th needle (you can do this without it but it's trickier so until you get the rest down, grab the other needle.
You will end the turning of the heel on the last right side row, now with your two free needles, you will pick up and knit all of the slip stitches down the side until you reach the neglected needles. on the last one, pick up one extra stitch from the row below to close the gap that you will have otherwise.
Knit across the top of the foot in k3 p1 rib AND transfer the stitches from Needle 2 and 3 onto one needle
THERE IS NO MAGIC TO THIS AND YOU DON"T HAVE TO BE PERFECT!!! It doesn't even matter if you pick up the same number of stitches on both sides, it will work itself out later, just trust me!
Do the same thing in reverse on the other side
(again, the number of stitches doesn't really matter)
Now for some tricky needle maneuvering: At this point you should have 4 needles in play
Look at the needle that holds the heel, find the center (this is not always an even number and your sock will not explode if it is not) transfer half of the stitches to the first needle used to pick up stitches and the other half to the other needle used to pick up stitches.
So now you're back to 3 needles, you have Y (24) stitches on the front needle (now Needle #2)
and approximately Z +Z/2 (18) on each of the other 2 needles. (now Needle #1 & #3)
Round now begins at the back of the heel
Needle #1: k until last 3 stitches k2tog k1
Needle #2: k3 p1 across
Needle #3: k1 ssk k to end
Row #2: knit around staying in pattern on Needle #2
Now you will work in this pattern until
Needle #1 has Z (12) stitches
and Needle #3 has Z (12) stitches
IF YOU DON'T HAVE THE SAME NUMBER OF STITCHES ON ONE SIDE:
just decrease again on that side each row until you reach Z stitches
Then knit around staying in pattern on Needle #2 until the foot is 2inches shorter than your final length.
usually total sock length women = 9inches, men 10-11inches so you will stop at 7-9inches
Now you stop knitting in pattern and do these two rounds:
Needle #1: k until last 3 stitches k2tog k1
Needle #2: k1 ssk k until last 3 stitches k2tog k1
Needle #3: k1 ssk k until end
repeat these two rows until you have Z (12) stitches on front and Z (12) stitches on the back
end the round at the end of Needle #1
now for Kitchener stitch
transfer back stitches to 1 needle
with the yarn tail on the right side of your work, you now have a front needle and a back needle.
with a long tail and and yarn needle:
insert needle into front first stitch as if it purl, leave on needle pull yarn through
insert needle into back first stitch as if to knit, leave on needle pull yarn through
insert needle into front first stitch as if to knit, slip stitch off needle,
insert needle into front second stitch as if to purl, leave on needle, pull yarn through
insert needle into back first stitch as if to purl, slip stitch off needle,
insert needle into back second stitch as if to knit, leave on needle, pull yarn through
repeat until 1 stitch remains on front and back needles
insert needle into front first stitch as if to knit, slip stitch off needle
insert needle into back first stitch as if to purl, slip stitch off needle
pull yarn through, thread to inside of sock, pull, weave ends, and you're done!
OK to summarize:
X = total
Y = X/2
Z = X/4
start with X,
k1 p1 around
k3 p1 around
needle #1 sl k1/p back and forth Z times
s1 knit Z k2 ssk k1 turn
s1 p5 p2tog p1 turn
knit to gap ssk k1 turn
purl to gap p2tog p1 turn
until stitches all knitted
pick up Z stitches on side, knit across top, pick up Z stitches on side
k to last 3 k2tog k1, k in pattern, k1 ssk k to end, knit around next row
continue until sides have Z stitches on each needle
knit until 2 inches short of total length of foot
k to last 3 k2tog k1, k1 ssk k to last 3 k2tog k1, k1 ssk k to end next round knit around
repeat until Z stitches left on front and back
Kitchener stitch closed
I'll add pictures for the steps as I get around to taking them!
Let me know if you have suggestions on how to reword this to make sense!