How to knit an afterthought heel

A step-by-step pattern for knitting an afterthought heel; plus a super smart alternative you can use for mending.

The afterthought heel is unique among all heel patterns in knitting for two reasons: First of all, it allows you to continue a pattern uninterrupted in the direction of the heel. This makes it fantastic for self-stripping yarn, colorways, or any other complex design. Secondly, you add it after knitting the shaft. This makes it ideal for mending bigger holes in your heels.

This tutorial will show you two different versions to start the afterthought heel. The first one is a bit easier but ironically requires some fore-thought. The second version creates a slightly bigger gap (easy to cover up!) but is a bit more versatile.

In addition, the afterthought heel does not require any short-row shaping and you don’t need to pick up any stitches from an edge either. The only downside is that you need to finish it with a Kitchener stitch.

Let’s show you how to knit it, eh?

Important details ahead:

Like many other heels (like the German short-row heel or the heel-flap and gusset), you typically work the afterthought heel across half of your stitches.

E.g. Cast-on = 52 st
-> Heel stitches = 26 st

You can knit it with circular or double-pointed knitting needles – whatever you prefer. I personally prefer dpns as you are less likely to stress the gaps and it’s a bit easier to knit those last 5 rounds. If you are proficient with the magic loop technique, I’m sure you already know how to work around these little issues.

If you prefer to knit your socks toe-up, then the pattern for the afterthought heel won’t change. It’s perfectly symmetrical and can be used no matter your knitting direction.

The afterthought heel is quite fitted. It’s perfect for slender feet. It typically does not end up with a bit of extra fabric that bunches up on your instep. That being said, if you have a high instep and need a roomier heel, it’s often not the best choice without further modifications (see below).

Part I: Afterthought heel setup

The easiest version to knit an afterthought heel requires a bit of preparation & simple planning. It’s perfect if you know the exact size & measurements of the intended wearer.

Step 1: Knit the cuff & calf of your socks as usual and according to your pattern. Stop right at the point where you want to place your heel. Your work in progress should barely cover your ankle.

Note: If you are working toe-up, you need to read ahead and calculate your heel first to know exactly where to stop. It’s the exact same calculation as the second version of the afterthought heel I show you a bit later in this article. You need to do a simple calculation regardless of your knitting direction. Just at different points in time.

Step 2 (optional): Use a tapestry needle and some fishing line or dental floss, and pull a lifeline through the stitches you want to work your heel across. I never do it but some beginners might find the extra security the lifeline offers reassuring.

Step 3: Pick up a short length of yarn in a nice contrasting color (can be a slightly different yarn weight) and knit across half of your stitches. Then break the yarn leaving a short tail on either side. Do NOT use a special joining technique or weave in the tails but let them dangle down as they are. The first and last two stitches will be a bit looser but that does not matter at all.

For a roomier heel, you can also knit across more than half of your stitches. Instead of half of the stitches, simply add 1-4 stitches on either side. I wouldn’t add more than that, though.

Step 4: Slide all the stitches you’ve knitted back to your left needle to the point where your (old) working yarn is still attached. If you are working with double-pointed knitting needles, you can simply turn your work in progress around.

Step 5: Pick up your (old) working yarn again and work across in pattern for one round.

Step 6 (optional): Add another lifeline by going through the stitches above your scrap yarn.

Step 7: Continue in pattern and finish the socks as if you’d already attached the heel until it’s time to start working on the toes. For now, you’ve only added an easily removable extra half-row of knit stitches.

Part II: Where to place the heel and when to start the toes

Probably the most important and most common question when working on socks is: “When do I start knitting the toes?”. The only way to answer that when knitting an afterthought heel is a simple calculation. It sounds scary but it’s literally entering two numbers into a calculator and measuring your work in progress.

Step A: Step on a piece of paper and use a pen/pencil/sharpie to create an outline of your foot.

Step B: Calculate the length of your heel

I) You work the heel across half of your stitches. Later on, you will pick up stitches on either side of the scrap yarn you’ve added (see step 8 below). So you will pick up half of your cast-on stitches twice.

E.g. 52 st ÷ 2 = 26 st
26 st * 2 = 52 st

So, the total number of stitches you will have to knit your afterthought heel will typically equal your cast-on.

If you added stitches for a roomier heel (see Part II step 3), adjust your calculation accordingly.

II) Subtract the stitches you will not decrease

The afterthought heel is decreased in a wedge shape similar to most toe box patterns. As a result, you will stop once there are only 16 stitches left and finish with a Kitchener stitch.

E.g. 52 st – 16 st = 36 st

This simple calculation will tell you how many stitches you will have to decrease.

Note: If you cast-on more than 80 stitches for your sock, I recommend calculating with 20 stitches for a less pointy heel. Of course, this means you will also have to stop knitting the heel when there are only 20 stitches left (see below; part IV).

III) Find out the number of heel rounds

You will decrease the afterthought heel by 4 stitches in every second round. With that knowledge, it’s easy to find out how many rounds you have to knit:

E.g. 36 st ÷ 4 st/r = 9 rows
9 rows * 2 = 18 rows

That’s how many rounds your afterthought heel will have.

Explanation for experienced knitters only: If you compare these calculations with the pattern below, you might notice that they will not align perfectly. However, the last three decrease rounds and the first three rounds without increases will balance themselves out. I’m just taking a shortcut here. Of course, the 4 increases you place in the first round will result in two more rounds. The Kitchener stitch will add another round. So a total of plus 3. However, you also remove one round (the scrap yarn) and your heel is not actually flat but rounded towards the end. In my experience, these factors balance themselves out.

Step C: Measure your work-in-progress

The best part of knitting an afterthought heel is how easy and reliable it is. You already have a sizeable piece of knitting in front of you that you can use as your gauge swatch.

Simply count however many rows your calculation said you need for your heel (e.g. 18 rows) and use a reliable tape or ruler to measure how many centimeters or inches you need to cover those rows. Make sure to stretch out your work in progress a bit. After all, you will stretch out your fabric a bit as you wear your socks later on as well.

Eg. 18 rows = 5.4 cm/2.1 in

Step D: Use the outline to figure out the toe placement

I) Starting from the heel of your outline, simply add a line right after the heel length you’ve recorded in the previous step. E.g. after 5.4 cm.

II) If you plan to knit a standard wedge-shaped toe box, add another line right in the middle of your pinky toe. For most people, that’s the point where your foot is getting narrower.

Note: If you use a different toe-box pattern, you’d have to go through it and figure out how many rounds you will knit. Then use a tape measure to adjust the line for the toes.

III) Place your work in progress on top of the outline and align the start-of-the-heel line with the half-round worked in the scrap yarn.

IV) You can start knitting your toes when your work in progress reaches the middle of your pinky toe. Remember to stretch your work in progress a bit to account for the difference after blocking/wearing.

Part III: Picking up Stitches

Once you’ve figured out the size of your heel, the rest is just as simple.

Step 8: Finish your socks according to your pattern & calculations.

Step 9: Pick up all the stitches below and above your scrap yarn. It’s easier to do this with smaller knitting needles but with a bit of squeezing you can also use the same. If you use smaller needles, absolutely remember to switch back to your original size as you start the first row!!

Close-up, a knit stitch looks like a “V”. And you always have to pick up the right leg of this V. Start on the right side with the stitch right below the first scrap yarn stitch and pick up stitches all the way across to the other side. Make sure that you don’t accidentally split the yarn.

Then, turn your work upside down and do the same on the other side. Pick up the same number of stitches on the other side of the divide by always going through the right leg of those Vs.

Note: If you placed a lifeline, you can also unravel the scrap yarn first and then pick up stitches from your lifeline. I personally feel that is a bit more difficult/fiddly but maybe it’s easier for you to process.

Step 10: Remove the scrap yarn by pulling it out carefully with your knitting needle or a tapestry needle. Make sure to trim the tail ever so often to avoid pulling the full length through each stitch. This would slightly grind down the yarn and compromise the integrity of your heel.

Part IV: The Afterthought Heel Pattern:

Round 1: Pick up the yarn you want to use for your heel. Do not use a special joining method. You can use the tail to fill any remaining gaps using duplicate stitches later on.

Start with a KRL. Place a stitch marker below to mark your beginning of the round. Knit across until you come to the gap on the other side (if you are using dpns, join in a second needle in the middle). Knit a KLL on the right side of the gap, place a stitch marker below, knit a KRL on the left side of the gap, and knit across the other side. Finish the row with another KLL.

Keep a nice and tight tension as you bridge the gap. It helps to tighten up after the second stitch.

Round 2-3: Knit across 2 more rounds.

Round 4: k1, SSK, knit until you are 3 stitches before the next stitch marker, k2tog, k1, slip marker, k1, SSK, knit until you are 3 stitches before the end of the round, k2tog, k1, slip marker.

Note: I always attach my stitch markers below. So I don’t actually have to slip them. They wouldn’t keep in place when working with dpns anyway. I use the gaps between the needles as orientation.

Round 5: knit across. Consider knitting all SSKs through the back loop for a neater finish.

Repeat rounds 4+5 until there are only 28 stitches left.

Last 3 rounds: Decrease in every round (so repeat round 4) until there are only 16 stitches left.

Finish the afterthought heel with a Kitchener stitch and weave in the tail on the wrong side.

Note: To avoid ears, I recommend skipping the 2 preparation stitches of the Kitchener stitch. Skip going through the last two stitches a second time as well and pull the tail to the wrong side by going right through the little hole below the last two stitches.

There’s a high chance the gaps still look a bit on the looser side. That’s because you put quite a lot of stress on these stitches as you’ve knitted your heel. You can use a knitting needle to carry over the slack and distribute it among the adjacent stitches.

Since two stitches are pulling on one stitch in two different directions, this will only get you so far. For the finishing touches, bring the tail back to the right side and cover the gap with 2-4 well-placed duplicate stitches. On the other side, you can do the same with a bit of scrap yarn.

Part V: Afterthought heel – Version B

This first version requires – as Elizabeth Zimmermann would have coined it – forethought. It’s not a true afterthought heel because you need to plan ahead when you place that half-row using the scrap yarn. There is, however, an alternative that is a bit more versatile.

It’s the perfect technique to mend a big hole in a sock heel or when you don’t know or remember the exact length of the foot but want to knit some socks as a gift.

Step 1: Knit the socks as normal but skip the heel. The result should be one long tube with a cuff at the start and some toes at the end. Consider blocking it. Often, your work in progress stretches out during that process and it will give you more reliable base for the calculations.

Step 2: Go through the heel calculations as detailed above (Part II), create an outline of the foot, and mark the place where the heel needs to start.

If you only have the shoe size, then you can easily figure out the total length of the foot. Use a ruler to mark the start and the end of the foot. Then draw a line where the heel should start.

Step 3: Overlay your finished sock tube with your sketch and use a stitch marker to mark the round where your heel needs to start.

Step 4: Pick up the required number of stitches (typically half your cast-on) from the rounds directly above and below the round where you placed your stitch marker. Always go through the right leg of the knit stitch Vs and pick up an equal number of stitches on either side.

Again, it’s easier to do this with slightly smaller knitting needles.

At the end, there should be one row in between with no needles/cables going through.

Step 5: Using a knitting needle, pull out the centermost stitch of the round in between and cut it (This is to avoid accidentally cutting into a stitch a row above or below). Then carefully unravel this (half) round towards both sides.

STOP right once you’ve released the last stitch still secured by your knitting needle. Do not unravel any further. Lightly secure the two tails on the inside for now. We will need them later on.

Step 6: Shuffle stitches around so the two gaps end up in the middle of your knitting needles. You do not want your magic loop/dpns gaps to align with the gaps of your afterthought heel (as in the picture above). This is a fail-safe recipe for huge holes and putting too much stress on these gap stitches.

This may feel as if you are moving the start of your round. But since you are unraveling one continuous round, you get to decide where to start your project anew. So, why not do it in a place where you do not add structural instability to the already problematic gaps?

Step 7: Join in your yarn on whatever side you prefer and knit across until you come to the first gap. You may weave in one tail as you go.

When using this second method, the gaps will bridge one round (the round you’ve partially unraveled). They will thus be bigger and you need a different method to pick up stitches to prevent large holes. Here’s how I do it:

I find the last stitch of the round I unraveled. This stitch will sort of appear to hang horizontally between the gap. This knit stitch has two little strands on either end hidden below the two legs. I lift those two strands back to the knitting needle one at a time and knit them through the back loop.

For even better coverage, you can add lifted increases on either side as well. So, you start with a KLL, then lift back the two strands one at a time and ktbl, and finish with a KRL.

Next, knit across until you come to the second gap and fill it in the exact same way by lifting those two strands back to the knitting needle one at a time and knitting them through the back loop. Then, knit across to the end of the round.

Step 8: From here, follow the same pattern as detailed above. So knit across two more rounds and then start decreasing by 4 stitches in every second round until there are 28 stitches left. Then decrease in every round until there are 16 stitches left. Finish with a Kitchener stitch.

Step 9: In the last step, you need to secure the two tails left from partially unraveling the round. Use them to cover any remaining little holes using duplicate stitches. You can also do this on the wrong side. Go all the way around the hole, loosely following the natural course of the knit stitches, and then pull tight.

Weave in the remainder of the tail the normal way.

Part VI: How to adjust the fit of an afterthought heel

If you follow these standard instructions, the afterthought heel will end up quite fitted. It’s not ideal for people with very high insteps or very wide feet, in my experience. That being said, there are ways to adjust it slightly.

You are free to combine these options as you see fit.

Option 1: Knit more rounds to add depth

If you look at the profile of your foot, you will notice that the heel actually sticks out a bit. Some people have a very pronounced heel that bulges out quite a bit further. The standard pattern above has you working across 3 rounds before you start decreasing. Nothing speaks against knitting 4, 5, or 6 rounds without decreases. This will create a deeper heel.

I wouldn’t add 10 rounds. This will not result in a pleasant fit or a balanced overall look. Please note that these additional rows potentially change the spot where you need to insert/start the heel.

Option 2: Knit across more stitches

I already mentioned that you can also knit the heel across more than half of your stitches to accommodate a wider heel. In this case, add 1-4 stitches on either side.

E.g. Cast-on = 52 stitches
-> Work the heel across 52 st ÷ 2 = 26 st
-> +2 stitches on either side: 26 st +2 st + 2 st = 30 st

Please be aware that this will take away fabric from your instep. So, don’t overdo this or you will end up with weirdly stretched stitches in that area.

Option 3: Add increases

Instead of working the first three rows plain, you can also add in a couple of increases. I recommend lifted increases since they are the most invisible for stockinette stitch but use whatever you prefer. Rounds 1-3 could look like this:

Round 1: Knit until you are 2 stitches before the first gap, KLL, k2, KLL, place marker, KRL, k2, KRL, knit until you are 2 stitches before the second gap, KLL, k2, KLL, place marker, KRL, k2, KRL, knit to end of round.

(This included the lifted increase to fill the gap; if you are using the second method of the afterthought heel, then replace the innermost KLLs/KRLs accordingly)

Round 2: Knit across

Round 3: Knit until you are 2 stitches before the marker, KLL, k2, sm, k2, KRL, knit until you are 2 stitches before the next marker, KLL, k2, sm, k2, KRL, knit across to end of round.

Round 4: Knit across

Round 5: Start the decreases as detailed before.

Option 4: Add a gusset

As an alternative to these methods, you can also add a gusset. This will not work as an afterthought and will require some planning. The general idea is that you increase your sock tube symmetrically before the place where you add the scrap yarn and then decrease back to your original number of stitches right after that spot.

6 rows before the heel: Place stitch markers on either side of what’s going to be your heel. Typically, that’s half of your stitches.

E.g.: cast-on = 52 st -> K13, place marker, k26, place marker, k13

Round 1: knit across until you are 3 stitches before the sm, place a marker, k1, KLL, k1, KRL, k1, sm, knit across to the next sm, slip it, k1, KLL, k1, KRL, k1, place a marker, knit across until the end of the round.

Round 2: knit across

Round 3:kKnit across to the first sm, slip marker, k1, KLL, knit across until you are 1 stitch before the second sm, KRL, k1, slip marker, knit across to the third sm, slip marker, k1, KLL, knit across until you are 1 stitch before the fourth sm, KRL, k1, slip marker, knit across to the end of the round.

Round 4: knit across

Repeat rounds 3+4 one more time

Round 7-1: insert your scrap yarn in between the second and third stitch markers.

Round 7-2: knit accross

Round 8: knit across to the first sm, slip marker, SSK, knit across until 2 stitches before the second sm, k2tog, slip marker, knit across to the third sm, slip marker, SSK, knit across until you are 2 stitches before the fourth marker, k2tog, slip marker, knit to end of the round

Repeat round 7+8 two more times, then continue according to your pattern.

Important: This is just one version to insert a gusset. Please note that the number of increase rounds you want to include will depend on your preferences and, of course, your gauge.

If you are working with 100 stitches in the round and 1.75mm needles, 3 increase rounds will probably be not even remotely enough, while with 3.5mm needles and 40 stitches, it might already be too much.

A gusset like this also gives you the opportunity to decrease below your original number of stitches. This can be useful if you have a very pronounced heel and stronger calves but somewhat slender feet.

Anyway, that’s how to knit an afterthought heel. Comment below if you have any questions.