Rainbow Granny Square Blanket: Free Crochet Pattern for Beginners and Beyond

There is something deeply satisfying about a granny square. It’s one of those timeless crochet motifs that has survived every trend cycle, found its way into the hands of grandmothers and teenagers alike, and somehow manages to feel both vintage and completely modern depending on the color palette you choose. This Rainbow Granny Square Blanket pattern brings all of that classic charm into a cheerful, colorful project that works up beautifully whether you’re picking up a hook for the first time or you’ve been crocheting for years.

This free pattern walks you through every step, from the materials you’ll need to the finishing touches that make a blanket look truly polished. By the end, you’ll have a cozy, vibrant throw blanket made from dozens of individual granny squares joined together in a wash of rainbow color. It’s the kind of project people notice when it’s draped over your couch. It’s also the kind of project that makes a genuinely wonderful gift.

Let’s get into it.

Why Granny Squares Are Perfect for Beginners (and Why Experts Keep Coming Back)

Before we dive into the pattern itself, it’s worth talking about why granny squares have such enduring appeal. If you’re new to crochet, the granny square is one of the best first projects you can attempt. You’re working in the round rather than back and forth in rows, which means you always have a clear visual sense of where you are in the pattern. Each square is small and manageable — you can finish one in about 20 to 30 minutes once you get the hang of it — so the progress feels constant and rewarding.

For more experienced crocheters, granny squares offer a different kind of appeal. They’re meditative and portable. You can toss a few squares’ worth of yarn into your bag and work on them while traveling, watching television, or sitting outside. The repetitive nature of the motif is exactly the kind of low-stakes crochet that lets your hands stay busy while your mind wanders freely. And when it comes time to join your squares and see the finished blanket come together, that moment of revelation — suddenly, individual motifs becoming one cohesive piece — never gets old.

This particular pattern uses a rainbow color arrangement, meaning each square is worked in a different color of the spectrum. The overall effect is joyful and bold. You can, of course, swap out the rainbow palette for anything that suits your taste. Muted earth tones, a monochromatic palette in shades of one color, or a random scrappy arrangement using leftover yarn from other projects all work beautifully with this pattern.

Materials You’ll Need

Getting your materials sorted before you begin will make the whole process smoother. Here is everything you need to complete this blanket.

Yarn: You’ll want a worsted weight yarn, sometimes labeled as a size 4 on the skein. This is the most common weight and is easy to find in just about any craft store. For the rainbow version of this blanket, you’ll need at least seven colors — one for each color of the rainbow: red, orange, yellow, green, blue, indigo (or a deep violet-blue), and violet. You’ll also want a neutral color for the border rounds of each square and for the joining. White, cream, or gray all work well. As a rough guideline, plan for about 200 yards of each rainbow color and around 800 to 1,000 yards of your neutral. This will make a throw-sized blanket of approximately 48 by 60 inches, which requires about 80 squares arranged in an 8-by-10 grid.

Hook: A size 5.0mm (H/8) crochet hook pairs perfectly with worsted weight yarn. If you tend to crochet tightly, consider going up to a 5.5mm hook. Your tension affects your finished square size, so a quick gauge swatch is always worth the few minutes it takes.

Additional supplies: A yarn needle for weaving in ends, scissors, and stitch markers if you like using them. A blocking mat and pins are optional but recommended if you want perfectly uniform squares.

Understanding the Stitches

This pattern uses only a handful of basic crochet stitches, which is part of what makes it so beginner-friendly.

A chain stitch forms the foundation of your work and is how you begin every round. A slip stitch is used to join rounds and move your yarn to the next position without adding height. A double crochet is the main building block of the granny square itself. You’ll work double crochets in groups of three, which are called clusters or shells depending on who you ask. A chain-two space at each corner is where the magic of the granny square happens — it creates the open corner that gives the motif its signature look.

If you’ve never crocheted before, spending 20 minutes practicing these four stitches before starting your first square will make a tremendous difference. There are countless video tutorials available online that demonstrate each stitch in real time, which can be easier to follow than written instructions alone.

The Granny Square Pattern

Each finished square, blocked, should measure approximately 6 inches by 6 inches with the hook and yarn described above.

Foundation ring: Begin by chaining 4 stitches, then join with a slip stitch to the first chain to form a ring.

Round 1: Chain 3 (this counts as your first double crochet throughout the pattern). Work 2 double crochets into the center of the ring. Chain 2. Work 3 double crochets into the ring. Chain 2. Repeat this sequence two more times, so that you have four clusters of 3 double crochets separated by four chain-2 corner spaces. Join with a slip stitch to the top of your beginning chain-3. You should now see a small square taking shape. Fasten off this first color if you’re doing a multicolored square.

Round 2: Join your second color (or continue with the same color) in any corner chain-2 space. Chain 3, then work 2 double crochets into the same corner space. Chain 2. Work 3 double crochets into the same corner space again. You’ve now completed one full corner. Chain 1. Move to the next corner space and work 3 double crochets, chain 2, 3 double crochets again. Chain 1. Repeat around the remaining two corners. Join with a slip stitch to the top of the beginning chain-3. Fasten off if changing colors.

Round 3: Join your neutral color (white, cream, or gray) in any corner chain-2 space. Chain 3, work 2 double crochets into the same space, chain 2, work 3 double crochets into the same space. Chain 1. Work 3 double crochets into the chain-1 space along the side. Chain 1. Work the full corner sequence (3 double crochets, chain 2, 3 double crochets) into the next corner. Chain 1. Work 3 double crochets into the side chain-1 space. Chain 1. Repeat around. Join and fasten off.

Round 4: Join your neutral color again (or continue without fastening off). This final round creates a solid border around the square that will make joining much easier and give the finished blanket a clean, unified look. Work a single crochet around the entire square, placing 3 single crochets into each corner chain-2 space to keep the corners crisp. Join and fasten off, leaving a tail for weaving in.

For the rainbow arrangement, make approximately 11 or 12 squares in each color. This will give you 80 squares total (with a few extras in case any don’t block out perfectly), which fills the 8-by-10 grid cleanly.

Blocking Your Squares

Blocking is the step that transforms a lumpy, curled-up square into a flat, neat, professional-looking motif. It sounds intimidating but it’s genuinely simple, and the difference it makes is striking.

Wet blocking is the most common method for acrylic and wool-blend yarns. Submerge your finished squares in cool water and let them soak for about 15 minutes until fully saturated. Gently squeeze out the excess water — do not wring them — then lay each square on a blocking mat. Use pins to stretch each square into a 6-inch-by-6-inch shape, checking with a ruler as you go. Pay particular attention to the corners, making sure they’re sharp and the chain-2 corner spaces are open and defined. Let the squares dry completely before removing the pins. This can take anywhere from a few hours to overnight depending on humidity.

If you’re working with 100% acrylic yarn, you can also steam block. Hold a steam iron an inch or two above the surface of the square (never directly touching the yarn) and allow the steam to penetrate the fibers. Gently pat the square into shape and let it cool before moving it.

Joining the Squares

Once all of your squares are blocked and you’ve laid them out in your preferred color arrangement, it’s time to join them into a blanket. There are several methods for joining granny squares, and each creates a slightly different look.

The flat slip stitch join creates a subtle visible seam on the right side of the work. Hold two squares with wrong sides facing each other, insert your hook through both layers of a corner stitch, and slip stitch across, working through corresponding stitches on both squares. This is fast and sturdy.

The join as you go method involves attaching each square to its neighbors as you work the final round of each new square. This eliminates the need for a separate joining step but requires more planning and attention as you go.

The whip stitch join is done with a yarn needle rather than a hook. With wrong sides together, use your needle to pass yarn through the outer loops of corresponding stitches on both squares, creating a visible diagonal line along the seam. This is a great option for beginners who find hooks fiddly during joining.

For this blanket, working in your neutral color and using the flat slip stitch join gives a cohesive finished look where the seams blend into the neutral borders of each square.

Join your squares in rows first, connecting each square to the next horizontally until you have 10 rows of 8 squares each. Then join the rows together vertically. Working in this order makes the whole process far more manageable than trying to join randomly.

The Outer Border

An outer border is what elevates a joined blanket from “collection of squares” to “finished heirloom piece.” It frames everything, smooths out any uneven edges along the perimeter, and gives your eyes a satisfying place to land.

Join your neutral yarn at any corner of the blanket. For a clean, simple border, work three rounds of single crochet around the entire perimeter, placing 3 single crochets in each outer corner to keep the blanket lying flat. At the end of each round, join with a slip stitch and begin the next round without turning.

For a more decorative border, the final round can be worked as a shell stitch border or a picot edge. A shell stitch border involves working (1 single crochet, skip 2 stitches, 5 double crochets, skip 2 stitches) all the way around, creating a scalloped edge. A picot edge is created by working a single crochet, then chaining 3 and slip stitching back into the same stitch before moving on — this adds tiny loops that give a delicate, lacy look.

Whichever border you choose, finish with a slip stitch join, fasten off, and weave in all remaining ends.

Tips for a Beautiful Finished Blanket

A few things make the difference between a blanket that looks good and one that looks truly polished.

Weave in your ends as you go rather than saving them all for the end. After you finish each square, take two minutes to thread your yarn needle and weave each tail in securely, going in one direction and then back in the opposite direction for security. Doing this as you progress means you won’t face a mountain of ends at the finish line.

Keep your tension consistent from square to square. Your gauge can shift slightly depending on how you’re sitting, how tired you are, or how much your hands have warmed up. Blocking helps even things out, but trying to maintain consistent tension from the start means less work correcting variations later.

Arrange your colors before you start joining. Lay all of your squares out on the floor in the order you plan to join them, and step back to look at the overall composition. This is your chance to spread similar colors evenly, break up clusters of the same shade, and get a sense of how the finished blanket will look. Taking a photo with your phone helps you remember the arrangement once you start joining.

Don’t skip blocking. Even if you’re tempted. Even if your squares look pretty good. Blocking makes them look great.

Caring for Your Finished Blanket

To keep your rainbow granny square blanket looking its best for years, wash it gently. If you used an acrylic or acrylic-blend yarn, it’s almost certainly machine washable — check the label to be sure — but washing on a gentle cycle in cold water and laying the blanket flat to dry will help it hold its shape longer than machine drying will. If you used wool or a wool blend, hand washing in cool water and laying flat to dry is the way to go.

A Note on Making This Pattern Your Own

One of the greatest things about a pattern like this is how easily it adapts. You can use the exact same instructions and completely transform the look of the finished blanket just by changing your yarn choices. A version worked in soft pastels has an entirely different feeling than the bold rainbow version. A version done entirely in grays, creams, and whites with black joining looks graphic and modern. A scrappy version using small amounts of every yarn you own is one of the most satisfying projects a crocheter can make — it’s thrifty, creative, and no two are ever alike.

You can also adjust the size. Each square is approximately 6 inches, so scaling up or down is simple arithmetic. A baby blanket at 4 squares by 5 squares (20 squares total) works up quickly and makes a sweet gift. A king-sized bedspread at 16 by 20 squares is an ambitious long-term project that will become a genuine heirloom.

However you make it, and in whatever colors speak to you right now, this Rainbow Granny Square Blanket is one of those projects that you’ll come back to again and again. It’s the kind of pattern you memorize without trying to, that becomes a background hum in your crafting life, always there when you want something satisfying to make with your hands.

Happy crocheting.