Updated: 11 November 2026 by Sylwia (MyCrochetory)
This square blanket in the round started with a knitting pattern. Not even a crochet one! It had this scalloped edge, little waves all along the border, and I wanted the same thing in crochet.
I looked around for a stitch that could do it. The clamshell stitch turned out to be exactly right.
I used it first in my Clamshell Shawl. While I was making the shawl, I took photos of every step, and they became my clamshell stitch tutorial.
After the shawl, a blanket was the obvious next thing to make. But I didn’t want rows this time. I wanted the shells to go round.
So this square blanket in the round starts as a tiny square in the middle. It grows out toward the four corners, and every few rounds you get a new row of scallops. I still like watching them appear.
Below you’ll find the full free pattern for this square blanket in the round, plus my yarn, colors and tips for the clamshell spike. Want a printable copy with a stitch chart? Grab it on Etsy or Ravelry.
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Pin it now so this square blanket in the round is waiting for you when your hook is free.
Why Clamshells Love a Square Blanket in the Round
The clamshell looks harder than it is. Each shell is just three double crochet stitches.
What makes it a shell is where you put them. The clamshell spike goes down into the rows below, and those long stitches form the scallop.
In a square blanket in the round, the shells run along all four sides at the same time. It’s all one piece, so there are no squares to sew together at the end. I like that a lot.
Never tried the stitch? My clamshell stitch tutorial has photos and a video, so practice a small swatch before you start your square blanket in the round.
The Yarn and Colors I Used
Now the yarn. I made my square blanket in the round in Scheepjes Softfun, which is a mix of cotton and acrylic.
It’s smooth and soft, and it doesn’t itch. For anything that touches skin, I always choose soft yarn, so this matters to me.
I used five colors, Prussian, Cyclamen, Mustard, Lagoon and Snow. I had to have Mustard. It’s been one of my favorite colors for as long as I can remember.
Each color lasts for three rounds. So every stripe gets its own row of shells, and the colors move across the blanket a bit like waves.
Want your own palette for a square blanket in the round? Pick colors with clear contrast, so the scallops really pop.
Yarn substitutes
Softfun is sold out at LoveCrafts right now. For all five colors in one brand, Paintbox Yarns Cotton DK is the easiest swap, a 100% cotton DK with a huge palette. Midnight Blue, Raspberry Pink, Mustard Yellow, Washed Teal and Paper White come close to my five.
Cotton without acrylic feels a little firmer, so if softness is your top priority, try Lion Brand Coboo, a cotton and bamboo DK. It’s lovely and soft, but it has fewer colors to choose from.
Why You Turn After Every Round
One thing is different here. A lot of crochet squares are worked without turning, but with this square blanket in the round you turn after every round.
You flip it over and work the next round on the back side. Turning helps each round sit straight on top of the last one, so the square doesn’t start to lean.
Each round starts in a corner chain space. Put a stitch marker in all four corners and move them up as you go, and you’ll always know where you are.
Grow Your Square Blanket in the Round
What I love about a square that grows from the center is that you choose when to stop.
Keep repeating Rounds 5 to 28 until it’s the size you want. Stop earlier for a baby blanket, or keep going for a big throw for the sofa.
More rounds mean more yarn, so buy an extra ball or two. When it’s big enough, finish on one of the scallop rounds listed in the pattern, and your square blanket in the round gets a wavy edge all around.
Finishing Touches
Softfun is a cotton and acrylic yarn, so I block my square blanket in the round with steam. I pin it to a mat and pass a hot steam iron about half an inch above it, never touching the yarn.
Tassels are up to you. I think four little tassels in the corners look really sweet.
CLAMSHELL SQUARE BLANKET IN THE ROUND FREE PATTERN
- Purchase the ad-free, printable PDF with stitch chart here on ETSY or here on Ravelry.
- Add this pattern to your Ravelry Queue HERE.
- Pin it for later.
Copyright 2021 – 2026 MyCrochetory. All rights reserved. This pattern is property of Sylwia Kawczyńska @MyCrochetory. Please DO NOT sell the pattern and claim this pattern as your own. The pattern is for personal use only and may not be translated or reproduced in another language. Please respect my rights, DO NOT share or publish this pattern anywhere without my permission.
The clamshell stitch crochet blanket you make following this pattern is yours you are free to sell it, as long as you credit MyCrochetory as original designer. For more information, please, read Terms Page.
As a bonus in the ad-free, printable PDF, I’ve provided a stitch chart. If you’re a visual learner or if you just want to support my work you can purchase this crochet baby blanket pattern HERE on ETSY or HERE on Ravelry. Thank you and I hope you find it useful!
Materials & Tools:
- Yarn SCHEEPJES Softfun 50g =140m, 60% Cotton, 40% Acrylic.
Yarn A: 2401 Prussian – approx. 308m,
Yarn B: 2534 Cyclamen – approx. 392m,
Yarn C: 2621 Mustard – approx. 448m,
Yarn D: 2644 Lagoon – approx. 476m,
Yarn E: 2412 Snow – approx. 504m.
Yarn substitute: Paintbox Yarns Cotton DK 50g = 125m, 100% Cotton, Yarn A 3 balls, Yarn B 4, Yarn C 4, Yarn D 4, Yarn E 5. Or Lion Brand Coboo 100g = 212m, 50% Cotton, 50% Bamboo, Yarn A 2 balls, Yarn B 2, Yarn C 3, Yarn D 3, Yarn E 3.
- Hook size 4mm. Adjust hook size if necessary to obtain correct gauge.
- Tapestry needle (to weave and hide yarn ends).
- Scissors,
- 4 stitch markers.
Level:
Intermediate – clamshell stitch pattern.
Size after blocking:
Approx. 110cm x 110cm (43.3’’ x 43.3’’).
Gauge after blocking:
After 15 rounds square measures approx. 21 x 21cm (8.25” x 8.25”).
Gauge is not important for this project. However, changes might result in a different yardage requirements and the finished size.
Notes:
- The pattern uses US crochet terminology.
- If you are not familiar with the clamshell crochet stitch or need a refresher, check out my photo tutorial HERE before beginning your project.
- This square blanket in the round is worked in one piece from the center out but after each round you will turn your blanket and work on the backside.
- Each round builds on the next, and each round starts in the corner chain space.
- Place the stitch marker in every ch-2sp corner.
- You can also use yarn in different weights, but just know that the width will be different depending on your gauge.
- You can make this blanket as big as you like by adding or subtracting pattern repeats.
- In the parenthesis (…) there is a stitch counting for each round.
- If the previous round starts with a turning chain which counts as a stitch then work your last stitch of the next round in top of beginning turning chains, unless otherwise stated.
- Instructions in square brackets […] or in {…} are worked as many times as indicated.
- The stitch chart is included in the ad-free printable PDF here on ETSY or here on Ravelry.
Stitches & Abbreviations (US terms):
st(s) – stitch(es)
yo – yarn over
PM – place marker
M – marker
RPM – reposition marker
sp – space
sk – skip
clamshell spike – skip first slip stitch and work first double crochet one row below the next slip stitch (into the single crochet one row below this second slip stitch), work a second double crochet right below your last double crochet – into the single crochet two rows below and work the third double crochet by putting this stitch into exactly the same stitch that the first double crochet was placed, skip third slip stitch.
PATTERN
Read all Notes before you start.
Using Yarn A, start with a magic ring or with 5ch and sl st in the first st to close the round.
Round 1: ch1 (doesn’t count as a st), [3sc in the ring, ch2, PM] rep 4 times in total, slst in first sc of the round to close the round. Turn. (12sc, 4ch-2sp)
Round 2: 2slst in ch-2sp, ch1 (doesn’t count as a st), sc in ch-2sp, [sc in each st until next ch-2sp, (sc, ch2, RPM, sc) in ch-2sp] rep 3 times in total, sc in each st until next ch-2sp, sc in ch-2sp, ch2, RPM, slst in first sc of the round to close the round. Turn. (20sc, 4ch-2sp)
Round 3: 2slst in ch-2sp, ch3 (counts as a st), [hdc in next st, slst in next 3sts, hdc in next st, (dc, ch2, RPM, dc) in ch-2sp] rep 3 times in total, hdc in next st, slst in next 3sts, hdc in next st, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Change to Yarn B in final st. Turn. (28sc, 4ch-2sp)
Round 4: 2slst in ch-2sp, ch1 (doesn’t count as a st), sc in ch-2sp, [sc in next st, hdc in next st, clamshell spike, hdc in next st, sc in next st, (sc, ch2, RPM, sc) in ch-2sp] rep 3 times in total, sc in next st, hdc in next st, clamshell spike, hdc in next st, sc in next st, sc in next ch-2sp, ch2, RPM, slst in first sc of the round to close the round. Turn. (36sc, 4ch-2sp)
Round 5: Rep Round 2. (44sc, 4ch-2sp)
Round 6: 2slst in ch-2sp, ch2 (doesn’t count as a st), hdc in ch-2sp, {slst in next 3sts, [hdc in next st, dc in next 3sts, hdc in next st, slst in next 3sts] rep across until next ch-2sp, (hdc, ch2, RPM, hdc) in ch-2sp} rep 3 times in total, slst in next 3sts, [hdc in next st, dc in next 3sts, hdc in next st, slst in next 3sts] rep across until next ch-2sp, hdc in next ch-2sp, ch2, RPM, slst in first hdc of the round to close the round. Change to Yarn C in final st. Turn. (52sc, 4ch-2sp)
Round 7: 2slst in ch-2sp, ch1 (doesn’t count as a st), sc in ch-2sp, {hdc in next st, clamshell spike, hdc in next st, [sc in next 3sts, hdc in next st, clamshell spike, hdc in next st] rep across until next ch-2sp, (sc, ch2, RPM, sc) in ch-2sp} rep 3 times in total, hdc in next st, clamshell spike, hdc in next st, [sc in next 3sts, hdc in next st, clamshell spike, hdc in next st] rep across until next ch-2sp, sc in next ch-2sp, ch2, RPM, slst in first sc of the round to close the round. Turn. (60sc, 4ch-2sp)
Round 8: Rep Round 2. (68sc, 4ch-2sp)
Round 9: 3slst in ch-2sp, {slst in next st, [slst in next st, hdc in next st, dc in next 3sts, hdc in next st, slst in next 2sts] rep across until next ch-2sp, (slst, ch2, RPM, slst) in ch-2sp} rep 3 times in total, slst in next st, [slst in next st, hdc in next st, dc in next 3sts, hdc in next st, slst in next 2sts] rep across until next ch-2sp, slst in next ch-2sp, ch2, RPM, slst in third slst of the round to close the round. Change to Yarn D in final st. Turn. (76sc, 4ch-2sp)
Round 10: 2slst in ch-2sp, ch2 (counts as a st), {dc in next 3sts, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until 3slst remain before next ch-2sp, dc in next 3sts, (hdc, ch2, RPM, hdc) in ch-2sp} rep 3 times in total, dc in next 3sts, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until 3slst remain before next ch-2sp, dc in next 3sts, hdc in next ch-2sp, ch2, RPM, slst at the top of ch2 to close the round. Turn. (84sc, 4ch-2sp)
Round 11: Rep Round 2. (92sc, 4ch-2sp)
Round 12: 3slst in ch-2sp, {slst in next st, hdc in next st, dc in next 3sts, hdc in next st, slst in next st, [slst in next 2sts, hdc in next st, dc in next 3sts, hdc in next st, slst in next st] rep across until next ch-2sp, (slst, ch2, RPM, slst) in ch-2sp} rep 3 times in total, slst in next st, hdc in next st, dc in next 3sts, hdc in next st, slst in next st, [slst in next 2sts, hdc in next st, dc in next 3sts, hdc in next st, slst in next st] rep across until next ch-2sp, slst in next ch-2sp, ch2, RPM, slst in third slst of the round to close the round. Change to Yarn E in final st. Turn. (100sc, 4ch-2sp)
Round 13: 2slst in ch-2sp, ch3 (counts as a st), {dc in next 2sts, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until 2slst remain before next ch-2sp, dc in next 2sts, (dc, ch2, RPM, dc) in ch-2sp} rep 3 times in total, dc in next 2sts, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until 2slst remain before next ch-2sp, dc in next 2sts, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Turn. (108sc, 4ch-2sp)
Round 14: Rep Round 2. (116sc, 4ch-2sp)
Round 15: 3slst in ch-2sp, {hdc in next st, dc in next 3sts, hdc in next st, [slst in next 3sts, hdc in next st, dc in next 3sts, hdc in next st] rep across until next ch-2sp, (slst, ch2, RPM, slst) in ch-2sp} rep 3 times in total, hdc in next st, dc in next 3sts, hdc in next st, [slst in next 3sts, hdc in next st, dc in next 3sts, hdc in next st] rep across until next ch-2sp, slst in next ch-2sp, ch2, RPM, slst in third slst of the round to close the round. Change to Yarn B in final st. Turn. (124sc, 4ch-2sp)
Round 16: 2slst in ch-2sp, ch3 (counts as a st), {dc in next st, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until one slst remain before next ch-2sp, dc in next st, (dc, ch2, RPM, dc) in ch-2sp} rep 3 times in total, dc in next st, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until one slst remain before next ch-2sp, dc in next st, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Turn. (132sc, 4ch-2sp)
Round 17: Rep Round 2. (140sc, 4ch-2sp)
Round 18: 2slst in ch-2sp, ch2 (counts as a st), {dc in next 3sts, [hdc in next st, slst in next 3sts, hdc in next st, dc in next 3sts] rep across until next ch-2sp, (hdc, ch2, RPM, hdc) in ch-2sp} rep 3 times in total, dc in next 3sts, [hdc in next st, slst in next 3sts, hdc in next st, dc in next 3sts] rep across until next ch-2sp, hdc in next ch-2sp, ch2, RPM, slst at the top of ch2 to close the round. Change to Yarn C in final st. Turn. (148sc, 4ch-2sp)
Round 19: 2slst in ch-2sp, ch3 (counts as a st), {hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until next ch-2sp, (dc, ch2, RPM, dc) in ch-2sp} rep 3 times in total, hdc in next st, sc in next 3sts, hdc in next st, [clamshell spike, hdc in next st, sc in next 3sts, hdc in next st] rep across until next ch-2sp, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Turn. (156sc, 4ch-2sp)
Round 20: Rep Round 2. (164sc, 4ch-2sp)
Round 21: 2slst in ch-2sp, ch3 (counts as a st), {dc in next st, [dc in next st, hdc in next st, slst in next 3sts, hdc in next st, dc in next 2sts] rep across until next ch-2sp, (dc, ch2, RPM, dc) in ch-2sp} rep 3 times in total, dc in next st, [dc in next st, hdc in next st, slst in next 3sts, hdc in next st, dc in next 2sts] rep across until next ch-2sp, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Change to Yarn D in final st. Turn. (172sc, 4ch-2sp)
Round 22: 2slst in ch-2sp, ch2 (counts as a st), {sc in next 3sts, [hdc in next st, clamshell spike, hdc in next st, sc in next 3sts] rep across until next ch-2sp, (hdc, ch2, RPM, hdc) in ch-2sp} rep 3 times in total, sc in next 3sts, [hdc in next st, clamshell spike, hdc in next st, sc in next 3sts] rep across until next ch-2sp, hdc in next ch-2sp, ch2, RPM, slst at the top of ch2 to close the round. Turn. (180sc, 4ch-2sp)
Round 23: Rep Round 2. (188sc, 4ch-2sp)
Round 24: 2slst in ch-2sp, ch3 (counts as a st), {dc in next st, hdc in next st, slst in next 3sts, hdc in next st, dc in next st, [dc in next 2sts, hdc in next st, slst in next 3sts, hdc in next st, dc in next st] rep across until next ch-2sp, (dc, ch2, RPM, dc) in ch-2sp} rep 3 times in total, dc in next st, hdc in next st, slst in next 3sts, hdc in next st, dc in next st, [dc in next 2sts, hdc in next st, slst in next 3sts, hdc in next st, dc in next st] rep across until next ch-2sp, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Change to Yarn E in final st. Turn. (196sc, 4ch-2sp)
Round 25: 2slst in ch-2sp, ch1 (doesn’t count as a st), sc in ch-2sp, {sc in next st, [sc in next st, hdc in next st, clamshell spike, hdc in next st, sc in next 2sts] rep across until next ch-2sp, (sc, ch2, RPM, sc) in ch-2sp} rep 3 times in total, sc in next st, [sc in next st, hdc in next st, clamshell spike, hdc in next st, sc in next 2sts] rep across until next ch-2sp, sc in ch-2sp, ch2, RPM, slst in first sc of the round to close the round. Turn. (204sc, 4ch-2sp)
Round 26: Rep Round 2. (212sc, 4ch-2sp)
Round 27: 2slst in ch-2sp, ch3 (counts as a st), {hdc in next st, slst in next 3sts, hdc in next st, [dc in next 3sts, hdc in next st, slst in next 3sts, hdc in next st] rep across until next ch-2sp, (dc, ch2, RPM, dc) in ch-2sp} rep 3 times in total, hdc in next st, slst in next 3sts, hdc in next st, [dc in next 3sts, hdc in next st, slst in next 3sts, hdc in next st] rep across until next ch-2sp, dc in next ch-2sp, ch2, RPM, slst at the top of ch3 to close the round. Change to Yarn A in final st. Turn. (220sc, 4ch-2sp)
Round 28: 2slst in ch-2sp, ch1 (doesn’t count as a st), sc in ch-2sp, {sc in next st, hdc in next st, clamshell spike, hdc in next st, sc in next st, [sc in next 2sts, hdc in next st, clamshell spike, hdc in next st, sc in next st] rep across until next ch-2sp, (sc, ch2, RPM, sc) in ch-2sp} rep 3 times in total, sc in next st, hdc in next st, clamshell spike, hdc in next st, sc in next st, [sc in next 2sts, hdc in next st, clamshell spike, hdc in next st, sc in next st] rep across until next ch-2sp, sc in next ch-2sp, ch2, RPM, slst in first sc of the round to close the round. Turn. (228sc, 4ch-2sp)
Then, repeat Rounds 5 – 28 until desired length.
NOTE: If you want to follow my color pattern then work:
Rounds 28 – 30 with Yarn A,
Rounds 31 – 33 with Yarn B,
Rounds 34 – 36 with Yarn C,
Rounds 37 – 39 with Yarn D,
Rounds 40 – 42 with Yarn C,
Rounds 43 – 45 with Yarn E,
Rounds 46 – 48 with Yarn B,
Rounds 49 – 51 with Yarn C,
Rounds 52 – 54 with Yarn D,
Rounds 55 – 57 with Yarn E,
Rounds 58 – 60 with Yarn A,
Rounds 61 – 63 with Yarn B,
Rounds 64 – 66 with Yarn D,
Rounds 67 – 69 with Yarn E,
Rounds 70 – 72 with Yarn B,
Rounds 73 – 75 with Yarn C,
Rounds 76 – 78 with Yarn D,
Rounds 79 – 81 with Yarn E,
Rounds 82– 84 with Yarn A.
When you have the desired length, I’d recommend that you end on either a repeat of Round 6 or Round 9 or Round 12 or Round 15 or Round 18 or Round 21 or Round 24 or Round 27, so you finish with a fabulous scalloped edge.
Fasten off yarn, weave in all ends and block your blanket. Add tassels to the corners in any color you like (optional).
If you have any suggestions or have detected any mistakes, please feel free to email me at sylwia@mycrochetory.com
More Clamshell Patterns From Me
Like the scallops? So do I, and they keep showing up in my designs.
- Clamshell Shawl. The triangle shawl where my clamshell story started, full of bold scallops.
- How to Crochet the Clamshell Stitch. My step-by-step photos and video for the stitch behind this blanket.
More Free Crochet Blanket Patterns
Finished your square blanket in the round? Here are more blankets to make next. They’re all my own designs.
- Kalinda Blanket. Another blanket worked from the center out.
- Granny Pinwheel Blanket. Three-color granny squares in mustard, black and white.
- Tonnta Wave Blanket. Colorful waves, with a video to follow.
- Cable Diamond Blanket. Crochet cables in a cuddly baby blanket.
- Carina Rectangle Blanket. A mosaic crochet blanket full of pattern.
- Thassos Mosaic Blanket. More mosaic crochet, in a bold blanket.
Looking for a new edge or stitch for your next one? Browse my easy crochet borders and crochet stitches for blankets.
Clamshell Square Blanket FAQ
Can I use a different yarn?
Yes. Any yarn works, but a different weight changes the size of your square blanket in the round and how much yarn you need. For a baby blanket, choose something soft and easy to wash.
Is this square blanket in the round good for beginners?
It’s an intermediate pattern. If you know your basic stitches and practice the clamshell spike on a swatch first, an adventurous beginner can do it.
Where can I find the stitch chart?
The stitch chart is in the printable PDF on Etsy and Ravelry. New to charts? Here’s how to read crochet charts.
Can I sell the blankets I make?
Yes, you can sell blankets made from this pattern, as long as you credit MyCrochetory as the designer. The full rules are on my Terms page.
Show Me Your Blanket
Made your own square blanket in the round? I’d really like to see which colors you picked. Tag #mycrochetory on Instagram, or share it in my Facebook Group or Ravelry Group.
Stuck on a round? Ask in the comments below. You can also follow me on Instagram, Facebook and Pinterest.
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