Rectangle Blanket Cardigan

Wrap yourself in pure comfort with this gorgeous, drape-friendly rectangle blanket cardigan that works up in just a few cozy evenings.

Have you ever stared at a gorgeous crochet sweater and thought, "There is no way my hands can make that"? I used to feel the exact same way. The fear of complicated shaping, armhole decreases, and endless sleeve adjustments kept me making basic blankets for years.

Traditional garment patterns can feel like a math exam. One wrong stitch count on a sleeve cap, and suddenly your left arm looks twice as long as your right.

You do not need complicated math.

In fact, you only need to know how to crochet a simple, flat rectangle. By using a clever folding trick and a lacy, repetitive stitch pattern, you will transform a basic block of crochet fabric into a cozy, boutique-style wrap.

This project is incredibly fast. Most crocheters can finish the entire piece in about seven hours.

The loose, oversized fit makes it feel like a wearable hug. Whether you are running errands on a crisp autumn morning or lounging on the couch, this cardigan adds instant, effortless style to any outfit.

Why You'll Love This Pattern

• Zero Complex Shaping: No tricky armhole decreases or sleeve caps to worry about.
• Incredibly Fast: The open, lacy stitch pattern means your fabric grows rapidly, finishing in just a weekend.
• Stunning Drape: The combination of worsted weight yarn and a larger hook creates a soft, flowing silhouette that flatters every body type.

Materials You'll Need

• Yarn: Lion Brand Vanna's Choice (Worsted weight, size 4; 170 yards per skein). We used the shades Linen and Rust for our sample, but any soft worsted weight yarn will work beautifully.
• Hook: Size J (6 mm) crochet hook, or whichever size you need to match the gauge.
• Notions: A sturdy tapestry needle for weaving in ends, and one large decorative wooden button (optional).
• Yardage: Approximately 700 (850, 1000, 1150) yards of worsted weight yarn.

Gauge & Sizing

• Gauge: Chain 30 + 4, then work Rows 1 through 5 of the pattern. Three shell repeats should measure exactly 5 inches across. Note that row gauge is not critical, as you can easily add or subtract rows to customize the width.
• Sizes included: XS/S, M/L, XL/2XL, 3XL/4XL.
• Finished measurements:
  • XS/S: 35 inches long (shoulder to bottom of ribbing) x 40 inches wide (sleeve to sleeve).
  • M/L: 38 inches long x 42 inches wide.
  • XL/2XL: 41 inches long x 44 inches wide.
  • 3XL/4XL: 41 inches long x 46 inches wide.

Abbreviations & Stitch Instructions

• ch: Chain
• sc: Single crochet
• dc: Double crochet
• tr: Treble crochet
• sl st: Slip stitch
• sk: Skip
• st(s): Stitch(es)
• fpdc: Front post double crochet. To work this, yarn over, insert your hook from front to back to front around the post of the indicated stitch, and complete a standard double crochet. For a detailed breakdown, check out our Crochet Post Stitch Guide.
• bpdc: Back post double crochet. To work this, yarn over, insert your hook from back to front to back around the post of the indicated stitch, and complete a standard double crochet.
• Shell: Work 5 double crochets directly into the specified chain-2 space.

Pattern Notes

• Skill Level: Easy / Advanced Beginner.
• This pattern is written in US crochet terms.
• The item is worked flat as a single large rectangle, then folded and seamed before adding ribbing in the round.
• Keep your foundation chain relatively loose. If your initial chains are too tight, the bottom edge of your cardigan will pull inward and warp the shape.
• You can easily adjust the height of your cardigan by changing the length of your starting chain. To adjust the width, simply work more or fewer row repeats.

Step-by-Step Instructions

Step 1: Crocheting the Main Rectangle

We will work this piece sideways from sleeve to sleeve. Leave a generous 1-yard tail of yarn before making your slip knot. This tail will be used for seaming later.

Chain 99 (109, 119, 119).

Row 1: Working directly into the back bumps of your starting chain, place 1 dc in the 5th chain from your hook. *Ch 2, skip the next 2 chains, then work 1 dc in each of the next 3 chains. Repeat from * across until you have only 4 chains remaining. Ch 2, skip 2 chains, then work 1 dc in each of the last 2 chains. Turn. [58 (64, 70, 70) dc]

Row 2: Ch 1, work 1 sc in the very first stitch. Skip the next dc. *Work a Shell (5 dc) in the next ch-2 space, skip the next dc, work 1 sc in the next dc, skip the next dc. Repeat from * across. After working your final shell in the last ch-2 space, skip the next dc, and place 1 sc in the top of the turning chain-3. Turn. [19 (21, 23, 23) shells]

Row 3: Ch 5 (this counts as your first treble crochet and a ch-1 space). Skip the next stitch. Work 1 dc in each of the next 3 stitches. *Ch 2, skip the next 3 stitches, then work 1 dc in each of the next 3 stitches. Repeat from * across until you reach the final shell. Ch 1, skip 1 stitch, and work 1 tr in the last sc. Turn. [59 (65, 71, 71) sts]

Row 4: Ch 3 (counts as your first dc). Work 2 dc in the first ch-1 space. Skip the next stitch, then work 1 sc in the next stitch. *Skip the next stitch, work a Shell in the next ch-2 space, skip the next stitch, work 1 sc in the next stitch. Repeat from * across until you reach the final dc group. Skip the next dc, work 2 dc in the next chain space, and place 1 dc in the next chain. Turn. [18 (20, 22, 22) shells with 2 half-shells on the ends]

Row 5: Ch 3 (counts as your first dc), work 1 dc in the next stitch. *Ch 2, skip the next 3 stitches, work 1 dc in each of the next 3 stitches. Repeat from * across until you reach the final shell. Ch 2, skip the next 3 stitches, work 1 dc in the next stitch, and place 1 dc in the top of the turning chain-3. Turn. [58 (64, 70, 70) dc]

Keep repeating Rows 2 through 5 in order until your entire piece measures 36 (38, 40, 42) inches wide. Make sure you finish on a double crochet row (Row 5) rather than a shell row. Cut your yarn, leaving another 1-yard tail for seaming, and fasten off.

Step 2: Folding and Seaming

Lay your completed rectangle completely flat. Make sure the right side (the side where your shell rows look clean and defined) is facing down.

Take the shorter ends of your rectangle and fold them inward toward the center until they meet.

Using your tapestry needle and the long yarn tail you left earlier, we will sew the side seams. Measure an armhole opening of 8 (8, 8, 8.5) inches from the fold.

Whip stitch the remaining portion of the side seam closed, working from the bottom edge up to your armhole marker. Repeat this process on the opposite side.

Step 3: Adding the Armhole Ribbing

Turn your cardigan right-side out. The ribbing is worked directly onto the right side of the fabric.

Round 1: Join your contrast color yarn with a slip stitch at the seam at the bottom of the armhole. Work 54 (54, 54, 58) sc evenly around the armhole opening. Slip stitch to the very first sc to join. Do not turn. [54 (54, 54, 58) sc]

Round 2: Ch 3 (counts as your first dc). Work 1 dc in each stitch around. Join with a slip stitch to the top of the starting chain-3. Do not turn. [54 (54, 54, 58) dc]

Round 3: Ch 2 (counts as your first bpdc). Work a fpdc around the post of the next dc. *Work a bpdc around the next dc, then a fpdc around the next dc. Repeat from * all the way around. Join with a slip stitch to the top of the starting chain-2. Do not turn.

Round 4: Ch 2 (counts as bpdc). Work a fpdc around the next fpdc. *Work a bpdc around the next bpdc, then a fpdc around the next fpdc. Repeat from * all the way around. Join with a slip stitch to the starting chain-2. Do not turn.

Round 5: Repeat Round 4 once more, or continue repeating it until your ribbed cuff measures approximately 2 inches wide. Fasten off. Repeat this entire ribbing process on the second armhole.

Step 4: Adding the Collar Ribbing

We will now work the cozy collar ribbing around the main opening of the cardigan.

Round 1: Join your contrast color yarn with a slip stitch at the center back of the collar opening. Work 256 (270, 284, 298) sc evenly around the entire opening. Join with a slip stitch to the first sc. Do not turn.

Round 2: Ch 3 (counts as first dc). Work 1 dc in each stitch around. Join with a slip stitch to the top of the starting chain-3. Do not turn.

Round 3: Ch 2 (counts as bpdc). Work a fpdc around the next dc. *Work a bpdc around the next dc, then a fpdc around the next dc. Repeat from * all the way around. Join with a slip stitch to the starting chain-2. Do not turn.

Round 4: Ch 2 (counts as bpdc). Work a fpdc around the next fpdc. *Work a bpdc around the next bpdc, then a fpdc around the next fpdc. Repeat from * all the way around. Join with a slip stitch to the starting chain-2. Do not turn.

Round 5 and beyond: Keep repeating Round 4 until your collar ribbing measures 3 inches wide. Fasten off.

Step 5: Optional Button and Loop

If you want to add a button closure, you can easily create a hidden loop. Locate a front post double crochet ridge on the inside of the collar, roughly 2 inches above the armhole seam.

Slip stitch twice to this ridge, keeping about half an inch away from the outer edge of the collar. Chain 36. Slip stitch in the second chain from your hook and in each chain back to the start. Fasten off, leaving a long tail.

Fold this chain in half to form a loop, and sew it flat against the collar edge. Sew your large wooden button on the opposite side of the cardigan, aligning it perfectly with the loop.

Easy Variations & Custom Ideas

• Solid Color Classic: Skip the contrast ribbing and work the entire cardigan in a single solid shade for a minimalist, modern look.
• Striped Blanket Style: Change colors every few rows of the main rectangle to create a bold, striped pattern. If you need help with clean transitions, check out our guide on Seamless Crochet Color Changes.
• Extra Long Cozy Version: Add 10 to 15 chains to your starting chain to create a longer, duster-style cardigan that falls below the knees.
• No-Button Open Front: Leave off the button entirely for a casual, flowing open-front cardigan that pairs perfectly with jeans and a t-shirt.
• Pocket Additions: Crochet two simple flat squares using the main stitch pattern and sew them onto the front of the cardigan for handy pockets.
• Colour ideas: Earthy tones like mustard, olive, and cream look stunning for autumn. Alternatively, try pastel shades like dusty pink and lavender for a soft spring vibe.
• Yarn substitutions: Any standard worsted weight yarn will work. Red Heart With Love, Caron Simply Soft, or Stylecraft Special DK (held double) make excellent substitutes.

Common Troubleshooting & Fixes

• Problem: The bottom edge of my cardigan is curving or pulling inward tightly.
  Fix: Your starting foundation chain was likely too tight. Pull it out and remake the chain using a hook that is one size larger, then switch back to your regular hook for Row 1.
• Problem: My shell stitches look messy or uneven.
  Fix: Make sure you are working all 5 double crochets directly into the chain-2 space, not into the individual chains themselves. This allows the stitches to fan out naturally.
• Problem: The armholes feel too tight or too loose.
  Fix: You can easily adjust the armhole size during the seaming step. Simply sew more or fewer inches of the side seam before fastening off.
• Problem: My stitch count is off at the end of a row.
  Fix: Always count your stitches on the double crochet rows (Rows 1, 3, and 5). It is very easy to accidentally skip the final stitch of a row, especially when working into the turning chains.

Care Instructions

To keep your cardigan looking beautiful, hand wash it in cool water with a gentle wool wash. Lay it flat on a clean towel to dry. Avoid hanging your cardigan to dry, as the weight of the wet fabric will stretch out the stitches and ruin the shape.

Final Thoughts

There is nothing quite like the feeling of wearing something you made with your own two hands. This simple rectangle cardigan proves that you do not need complicated patterns to create gorgeous, wearable fashion. Grab your hook, pick your favorite colors, and enjoy every single stitch!