My Sock Formula


So you have questions…who decides the number of stitches to cast on? where do these number of stitches come from? how do you know how many stitches to use for the heel flap or turning the heel?

Well, perhaps I can answer a few of them for you.

First I always use 5 needles when doing socks. It’s just easier for me when I am doing the math.
When I first learned to knit socks I always used someone else’s pattern and wondered how they knew how many stitches to cast on, how many to use for the heel flap and turning the heel, etc. After knitting many pairs of socks, it dawned on me how these numbers were figured out. And I want to share with you the conclusions that came to me.

Casting On

I have learned over the years many things about types of yarn, especially sock yarn.
Most sock yarn, or fingering weight yarn, will specify needle sizes on the paper wrap. Pay attention to that information.

I have learned that a US size 3 set of needles is the perfect size for most socks. The average number of stitches used with US 3 needles is 60 or 64. The end result will fit an average size lower calf. If you have a smaller calf, you may want to either use smaller needles or less stitches.

You will also want to cast on an even number of stitches. This makes it easier on you when doing the heel flap and the heel turn.

These numbers also work well with most patterns.

Heel Flap

The heel flap will ALWAYS be 1/2 of your total number of stitches.

Another thing to remember about the heel flap is its length. It must be long enough for you to pick up the correct number of stitches for the gusset. Well how do you figure this, you ask? Easy…

Every row on the heel flap begins with a slip stitch. On the knit row you will slip the first stitch and on the purl row you will slip the first stitch. So how do you figure the number of rows?

First, remember that the number of picked up stitches for the gusset on each side of the sock must be 1/4 of the total number of stitches cast on. So if you cast on 60 stitches, then the number of picked up stitches on each side must be 15 stitches each. Also keep in mind that the slipped stitches at the beginning of every row on your heel flap will cover two rows. In order to have the correct number of slipped stitches on each side of your heel flap you will need to knit 30 rows.

This same rule will apply to other cast on number of stitches: 64 stitches = 32 stitches for the heel flap and 32 rows so that you will have 16 stitches available to pick up in the gusset area.

Gusset stitches

When you pick up the gusset stitches, you will have to reduce them down to 1/4 of your total number of stitches. You do this by decreasing every other round. This makes the gusset area large enough to go over the largest part of the foot and then reduces it to accommodate the foot area.

Turning the heel

Now you have completed the heel flap, how do you figure the number of stitches to knit across before turning?

Divide the number by 3 in your head. So if you have 30 stitches on your needles, mentally divide by 3 = 10.
Your set up row will be like this: knit across the first 2/3 (20 stitches), then slip one, knit one, then pass the slipped stitch over the knit stitch, turn.

Next, slip the first stitch, then purl across the middle 1/3 (10 stitches), purl two together, turn.
Next, slip the first stitch, then knit across the middle 1/3 (10 stitches), slip one, knit one, pass slipped stitch over, turn.

You will notice that there is an equal number of unworked stitches on each end of the needle.
You will continue working the stitches back and forth until you have worked all stitches.

Okay, what about 32 stitches? How do you divide that evenly? Again, mentally divide by 3 = 10 with 2 left over. You will always want to work on even numbers, so add those 2 stitches to your middle 1/3. 10 – 12 -10 . This will make your unworked stitches even on each end. It is really annoying to have an extra stitch left over after you have worked all your stitches.

After completing the heel turn, you will pick up your gusset stitches and continue as described above until you reach the toe area.

Toe decreases

You will decrease at the end of one needle and the beginning of the next, twice (you have 4 needles, remember) every other round. So there will always be a round where you do not decrease in between your decrease rounds. You will continue until you have reached the desired number of stitches left. I ususally base this on how long the toe area is after I begin my decreases. I like my toe area to equal about 2 inches in length. So I usually stop decreasing when my remaining stitches reach a total of 24. Then I graft the toe.

I hope I have answered some of your questions. With this formula you can knit almost any sock pattern out there. So go for it. Knit those socks.

I almost forgot! How do you know how long to make your sock? Measure your foot. Keep in mind that your heel/gusset area is about 2 to 2 1/2 inches and your toe area is about 2 inches. Subtract that total from the measured length of your foot. This will tell you how long to make the area between the picked up stitches in the gusset to the beginning of your toe decreases.

A helpful tool you can use is a Sock It To Me card from Knit Picks. It gives you the total length of socks from heel to toe based on shoe size for men, women and children.


Basic Footies Pattern

If you can knit socks, you can knit these basic, easy footies.


1 set of 5 US 3 double pointed needles
1 50 gram skein of sock yarn solid color (I used Bernat Sox Sock yarn)
1 50 gram skein of sock yarn self striping (again Bernat Sox Sock yarn)
Tapestry or yarn needle for grafting the toe
Gauge: 7 stitches to the inch, 9 rows to the inch


C/O – cast on
K – knit
P – purl
Sl – slip
PSSO – pass slipped stitch over
DP – double pointed
CC – contrast color (solid)
MC – main color (stripes)
tog – together
PU – pick up


Using size 3 DP needles C/O 60 stitches with CC and divide evenly over 4 needles (15 stitches). Join and begin K1, P1 rib around. Repeat for a total of 7 rounds.

Heel Flap:

Join MC, and S1, K1 across the next two needles …onto one needle so that you are working back and forth on one needle while doing the heel flap. Turn

S1, P across the needle.

Repeat these two rows until you have completed a total of 30 rows.

Turn the Heel:

Set up row: K 20 stitches. S1, K1, PSSO. Turn

a. S1, P10 stitches, P2tog. Turn
b. S1, K10 stitches, S1, K1 PSSO. Turn

Repeat a and b above until all stitches have been worked.

K across the 12 stitches


PU 15 stitches along the side and knit. You will have 15 + 12 stitches on one needle. This will be reduced in just a moment.

K across the next two needles.

PU 15 stitches along the next side and knit. AND knit 6 stitches from your first needle. You now have 21 stitches on needles 1 & 4 and 15 stitches on needles 2 & 3. Your starting/ending will now begin in the middle of the heel.

Reduce the Gussett Stitches:

Round 1:

K up to last 3 stitches, K2tog, K1
K the stitches on the next two needles
K1, S1, K1, PSSO, K remainder of stitches

Round 2:

K even (no decreases)

Repeat the above 2 rounds until you have decreased the number of stitches down to 15 on needles 1 & 4.


K even until the foot of the sock measures about 6 inches from the PU stitches.

Toe Decreases:

Needle 1. K up to last 3 stitches, K2tog, K1
Needle 2. K1, S1, K1, PSSO. K to end of needle
Needle 3. repeat needle 1
Needle 4. repeat needle 2

K one round even

Repeat above until you have 6 stitches left on each needle. Slip these stitches to 2 needles (12 stitches on each), making sure that your decrease stitches are on the ends of each needle. You will have to knit across one needle to get your yarn in position to graft the toe.

Using the kitchener stitch, graft the toe stitches. Work in all loose ends with your tapestry/yarn needle.

Repeat for other footie.