Mardava Shell Stitch Crochet Hat

Shell stitches twist together to create a bold, textured hem on the Mardava Hat. This 3D, shell stitch crochet hat pattern includes 7 sizes from preemie to adult. It’s a cozy and elegant way to keep warm on chilly days.

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Hat of the Month Club

I designed this scarf for the 2025 Hat of the Month Club crochet along (CAL). This year-long event is hosted by Rhondda from Oombawka Designs and Amy from The Stitchin Mommy. Follow along for 3 new scarf patterns every month!

The other two hat patterns this month are the Evergreen Mist Hat by Rhondda and the Autumn Leaves Chunky Beanie by Amy (coming soon!).

Scarf of the Month Club

Rhondda and Amy also run a Scarf of the Month Club. It works the same way as the hats, with each guest designer creating both a hat and a scarf for their month. Get the matching Mardava Cowl and make it a set!

Free PDF with Coupon Code!

As part of the CAL, you can get the pdf version of this striped crochet scarf pattern for FREE on Ravelry with a coupon code! But hurry, this code is only valid for a short time and then it’s gone!

Coupon Code: NovemberHat

Terms: This code expires at 11:59pm Eastern time on Monday, November 24, 2025. Please make sure the discount shows in your cart before completing checkout. Due to the fees involved, I cannot refund accidental purchases.

Paintbox Simply Aran Yarn

I made this crochet shell stitch hat with some leftover Paintbox Simply Aran yarn from the Flynnster Blanket. It’s a soft, worsted-weight, acrylic yarn with so many colors to choose from! For the sample, I used Vanilla Cream and Rich Teal.

3-Dimensional Shell Stitch

The shell stitches in this pattern are simple shells made of 5 double crochet, but with a twist that really makes them pop! Each shell is worked around the post of the first stitch in the shell below it. This makes the shells twist back on themselves, creating puffy pockets in a rippling, 3-dimensional texture.

Mardava Dimensional Shell Stitch Tutorial

Need a little help with the shell stitch used in this pattern? Check out this 3D shell stitch crochet tutorial!

Mardava Hat

Yarn weight and project level images source: Craft Yarn Council

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Sizes

Preemie [Newborn, Baby, Toddler, Child, Adult Small, Adult Large]

To Fit Head Circumference: 12-13 [14-15, 15.5-17, 17-19] [19-21, 21-23, 23-25]” / 30-32.5 [35-37.5, 39-42.5, 42.5-47.5] [47.5-52.5, 52.5-57.5, 57.5-62.5] cm

Hat Circumference: 12 [13.25, 14.5, 16.75] [18, 20.5, 21.5]” / 30 [33, 36.5, 42] [45, 51.5, 54] cm

Hat Height: 4 [5, 6.25, 7] [8, 8.5, 9.25]” / 10 [12.5, 15.5, 17.5] [20, 21.5, 23] cm

Gauge

10 hdc = 4″ / 10 cm after blocking, 9 rnds = 4″ / 10 cm after blocking

In Shell Stitch Pattern: 5 shells = 6″ / 15 cm after blocking; 9 rows/rnds = 4″ / 10 cm after blocking.

Note: This stitch pattern expands vertically when blocked. Exact gauge is not critical but will affect yardage needed.

Gauge Swatch in Pattern:

With either color, ch 18.

Row 1: Sc in back bump of 2nd ch from hook and each ch across. (17 sc)

Row 2: Ch 1, turn, hdc in each st across. (17 hdc)

Row 3: Ch 1, turn, hdc in first st, sk next st, [shell around next st, sk next 2 sts] 4 times, shell around next st, sk next st, hdc in last st. (5 shells, 2 hdc)

Row 4: Ch 1, turn, hdc in first st, [shell around first st of next shell] 5 times, hdc in last st.

Rows 5-12: Repeat Row 4.

Fasten off. Block swatch, stretching vertically to open up shells. Measure gauge across center of swatch, ignoring edges.

Abbreviations used

This pattern uses US terms.

Recommended Resources

• Mardava 3D Crochet Shell Stitch Tutorial
• How to Crochet into the Back Bump of a Chain
• Foundation Single Crochet (fsc) Tutorial

Special Stitches

Front Post Double Crochet (fpdc): Yo, insert hook from front to back and out to front again around post of indicated st, yo and draw up a loop (3 loops on hook), [yo and pull through 2 loops on hook] twice.

Front Post Half Double Crochet (fphdc): Yo, insert hook from front to back and out to front again around post of indicated st, yo and draw up a loop (3 loops on hook), yo and pull through all 3 loops on hook.

Foundation Single Crochet (fsc): Insert hook in ch at base of previous st, yo and pull up a loop, yo and pull through 1 loop on hook (ch made), yo and pull through both loops on hook (sc made).

Shell Stitch (shell): 5 fpdc around indicated st.

Instructions

Scroll down for Chart.

Shell Stitch Edge

Work is joined after the first sc row rather than at the foundation chain, which makes it easier to join without twisting. There will be a slight gap at the foundation chain, which will be closed later when weaving in ends.

Rnd 1 (RS): With A, ch 2, sc in 2nd ch from hook, 29 [32, 35, 41] [44, 50, 53] fsc, join with sl st to first st. (30 [33, 36, 42] [45, 51, 54] sts – multiple of 3.)

OR

Alternate Rnd 1 (RS): With A, ch 31 [34, 37, 43] [46, 52, 55], working in back bumps of chs, sc in 2nd ch from hook and each ch across, join with sl st to first st. (30 [33, 36, 42] [45, 51, 54] sts – multiple of 3.)

Rnd 2 (WS): Ch 1, turn, hdc in each st around, join with sl st to first st.

Rnd 3: Ch 3 (count as first fpdc of shell throughout), turn, 4 fpdc around first st (first shell made), [sk next 2 sts, shell around next st] around to last 2 sts, sk last 2 sts, join with sl st to first st. (10 [11, 12, 14] [15, 17, 18] shells)

To change colors at the end of a rnd, work the joining slip stitch with the new color. Carry A up in the first stitch of each round until needed again.

Rnd 4: Ch 3, turn, 4 fpdc around first st of first shell, shell around first st of next and each shell around, join with sl st to first st, change to B.

Rnd 5: Ch 3, turn, 4 fpdc around first st of first shell, shell around first st of next and each shell around, join with sl st to first st.

Rnd 6: Rep Rnd 5, change to A at end of rnd, fasten off B.

Sizes Baby, Toddler, Child, Adult Small & Adult Large only:

Rnds 7-8: Rep Rnd 5.

Body

Rnd 1 (RS): Ch 1, turn, 3 fphdc around first st of each shell around, join with sl st to first st. (30 [33, 36, 42] [45, 51, 54] sts)

Remainder of Hat is worked in continuous rounds. All remaining rnds are RS rnds. Do not join or turn.

Rnd 2: Ch 1, sc in first st, hdc in each remaining st around.

Sizes Newborn, Baby, Toddler, Child, Adult Small & Adult Large only:

Rnds 2-x [3, 4, 5] [7, 7, 9]: Hdc in each st around.

Crown

Setup Rnd: {Hdc2tog, hdc in next 3 [31, 7, 19] [7, 15, 7] sts} 6 [1, 4, 2] [5, 3, 6] time(s). (24 [32, 32, 40] [40, 48, 48] sts)

For remainder of Crown, each size starts on a different rnd number as indicated.

Sizes Adult Small & Adult Large Only:

Rnd 1: Hdc in next 2 sts, [hdc2tog, hdc in next 4 sts] 7 times, hdc2tog, hdc in last 2 sts. (40 sts)

Sizes Toddler, Child, Adult Small & Adult Large Only:

Rnd 2: [Hdc2tog, hdc in next 3 sts] around. (32 sts)

Sizes Newborn, Baby, Toddler, Child, Adult Small & Adult Large Only:

Rnd 3: Hdc in next st, [hdc2tog, hdc in next 2 sts] 7 times, hdc2tog, hdc in last st. (24 sts)

All Sizes:

Rnd 4: [Hdc2tog, hdc in next st] around. (16 sts)

Rnd 5: Hdc2tog around. Fasten off. (8 sts)

Finishing

Weave ending tail through sts of last rnd and pull tight to close, then weave in end.

Use starting tail to sew gap closed at bottom of row 1.

Weave in all ends.

Wash and block, stretching vertically to open up stitch pattern.

Chart

Chart shows Shell Stitch Edge and first 2 rounds of Body only.

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I hope you enjoyed this shell stitch crochet hat pattern! A downloadable pdf of this pattern is available on Ravelry for a small fee.

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