Crimson Diamond Crochet Beanie: Free crochet pattern

This beanie pairs a neat back-loop brim with a bold all-over diamond lattice built entirely from front post double crochets — no complicated clusters or special tools, just a hook and one beautiful skein of deep crimson yarn.

The lattice is worked in a four-stitch, four-round repeat that shifts the raised stitches one position each round to close the diamond and open the next. It looks intricate, but once you have the rhythm you will barely need to look at the pattern.

Sized for an average adult head with a few inches of negative ease so the hat sits snugly and holds its shape all day. Confident beginners who are comfortable working in the round and have tried front post stitches will finish this in an evening.

What you need

• 450 yards (410 m) worsted-weight yarn in deep crimson (100 g skein; acrylic, wool-acrylic, or acrylic-nylon blend all work well — choose one with good stitch definition so the lattice pops)
• 5.0 mm (US H/8) crochet hook
• 1 locking stitch marker
• Tapestry needle for weaving ends

Gauge

14 sc and 16 rounds = 10 cm (4 in) in single crochet with 5.0 mm hook. Gauge matters here: too loose and the hat will be baggy; too tight and it won't stretch over the head.

Abbreviations

• ch — chain
• sc blo — single crochet in the back loop only
• sc — single crochet
• FPdc — front post double crochet
• dec — sc 2 together (invisible decrease)
• tr — treble crochet
• dc — double crochet

Pattern notes

• The hat is worked in the round from the bottom up without turning.
• Place a stitch marker in the first stitch of each round and move it up as you go.
• Front post double crochets (fpdc): insert hook from front to back to front around the post of the stitch directly below, yarn over and complete as a normal double crochet. The raised ridge appears on the side facing you.
• Back-loop single crochets (worked into the back loop only) in the brim create a subtle horizontal rib that adds stretch.
• Rounds 8–11 form one full diamond repeat; work that four-round set five times in total (rounds 8–27) before moving to the crown.

1. Ribbed Brim

A foundation ring of 72 chains sets the circumference; six rounds of back-loop single crochet build the stretchy ribbed brim.

• Round 1: 72 ch [72] — Join with a slip stitch to the first chain to form a ring, being careful not to twist.
• Rounds 2–7: sc blo in each stitch around [72] — For round 2 work into the back bumps of the foundation chain; rounds 3–7 work into the back loops of the stitches below. The front loops left free give the brim its horizontal ribbed texture.

2. Diamond Lattice Body

The four-round repeat shifts a pair of fpdc stitches by one position each time, building the diamond grid that defines the hat.

• Round 8: (sc, FPdc, FPdc, sc) × 18 picked up evenly [72] — Pattern A: the two fpdc sit at the centre of each 4-stitch repeat, beginning the raised pair.
• Round 9: sc in each stitch around [72]
• Round 10: (FPdc, 2 sc, FPdc) × 18 [72] — Pattern B: the two fpdc sit at the edges of each repeat, closing the diamond above and opening the next below.
• Round 11: sc in each stitch around [72] — Rounds 8–11 are one full diamond repeat. Work rounds 8–11 four more times (rounds 12–27 total), then continue to crown shaping.

3. Crown Shaping

Eight evenly spaced decrease points draw the hat to a tidy closed crown over ten rounds.

• Round 28: (7 sc, dec) × 8 picked up evenly [64]
• Round 29: sc in each stitch around [64]
• Round 30: (6 sc, dec) × 8 [56]
• Round 31: sc in each stitch around [56]
• Round 32: (5 sc, dec) × 8 [48]
• Round 33: (4 sc, dec) × 8 [40]
• Round 34: (3 sc, dec) × 8 [32]
• Round 35: (2 sc, dec) × 8 [24]
• Round 36: (sc, dec) × 8 [16]
• Round 37: dec × 8 [8]

1. Cut yarn leaving a 15 cm (6 in) tail. Thread onto tapestry needle, draw through all 8 remaining stitches, pull snug to close the crown, and fasten off on the inside.

4. WithMe signature heart

The same little heart sits on every WithMe original — our way of signing it with love. Use any contrast colour from the project.

• Round 1: 3 tr, 3 dc, ch, tr, ch, 3 dc, 3 tr in a magic ring [15] — Ch 3 first (it doesn't count as a stitch). After the last stitch, ch 3 and sl st into the ring, then pull the ring tight — the dip at the top of the heart forms as you pull.

1. Fasten off, leaving a tail for sewing the heart in place.

Finishing

1. Weave in both ends securely on the inside of the hat.
2. Block lightly by dampening the hat, stretching it gently over a bowl or balloon inflated to roughly 56 cm (22 in) circumference, and leaving it to dry fully. This evens out the diamond lattice.
3. Sew the WithMe signature heart onto the lower right side of the brim, centred between two diamond columns, using the thread provided with the heart and a tapestry needle. Secure with a small knot on the inside.

Tips from the WithMe studio

• Keep your tension slightly looser than usual for the fpdc rounds — post stitches draw in and can make the hat too tight if worked firmly.
• Count your 4-stitch repeats at the start of every Pattern A and Pattern B round until the rhythm feels automatic. A single missed stitch shifts the whole diamond.
• If the foundation chain feels fiddly to join without twisting, chain 73, slip stitch into the second chain from the hook to start round 2, then close the gap when you weave in the tail.
• For a deeper brim, add 4 extra back-loop rounds (rounds 2–11 instead of 2–7) before starting the body; add roughly 60 yards of yarn.
• Worsted wool-acrylic blends block beautifully and the fpdc ridges spring back after washing, keeping the diamond pattern crisp wear after wear.

Share your make with #withmelove — we would love to see it.