Double Thick Kilometre Scarf: Free Knitting Pattern and Complete Guide

There is something deeply satisfying about a scarf that wraps around your neck not once, not twice, but as many times as you need it to. The kilometre scarf — sometimes called the infinity scarf of the straight-needle world — is one of those projects that experienced knitters return to again and again, and that beginners discover with genuine delight. When you make it double thick, you transform an already generous project into something that feels almost architectural: substantial, warm, beautifully structured, and endlessly wearable.

This free knitting pattern will walk you through every step of creating a double thick kilometre scarf, from choosing your yarn to casting off and finishing. Whether you are picking up needles for the first time or looking for a satisfying weekend project to add to your repertoire, this pattern is adaptable, forgiving, and deeply rewarding.

What Is a Kilometre Scarf?

The name says it all, almost. A kilometre scarf is an extra-long scarf, traditionally worked in a simple stitch pattern that keeps the fabric flat and reversible, designed to be wrapped multiple times around the neck. The length is what sets it apart from a standard scarf — typically ranging from 150 centimetres on the shorter end to 250 centimetres or more on the longer end, depending on the knitter’s preference and the thickness of the yarn.

The double thick version takes this concept further. Instead of knitting a single layer of fabric, you work a technique that creates two layers simultaneously, or you work the scarf and then fold and seam it to create a double layer. The result is a scarf with significantly more body and warmth, one that feels more like a soft collar or a wrap than a traditional flat scarf. The two layers trap air between them, adding insulation, and the extra weight makes the scarf drape beautifully.

Why You Will Love This Pattern

Before diving into the instructions, it helps to understand why this particular pattern has become a staple among knitters of all skill levels.

First, the construction is beginner-friendly. The double thick kilometre scarf relies on basic stitches — knit and purl — and uses a technique that is easy to master within the first few rows. If you can knit and purl, you can make this scarf.

Second, it is a genuinely useful project. This is not a decorative piece that sits in a drawer. A double thick scarf is warm enough for real winter weather, versatile enough to wear to work or on a weekend walk, and attractive enough to give as a gift. It is one of those items that people actually use, which makes the knitting feel purposeful.

Third, the pattern is highly customisable. You can change the yarn weight, the stitch pattern, the length, the width, and the colour, and each variation produces a noticeably different result. The basic structure remains the same, but the finished scarves can look entirely distinct from one another. This makes it a pattern you will come back to multiple times without feeling like you are repeating yourself.

Finally, the rhythm of the knitting is meditative. Long, relatively simple projects allow you to settle into a comfortable pace, listen to music or a podcast, and let your hands work while your mind rests. Many knitters describe projects like this as genuinely relaxing in a way that more complex patterns are not.

Materials You Will Need

For a classic double thick kilometre scarf, here is what to gather before you begin.

Yarn: Approximately 400 to 600 grams of bulky or super bulky yarn, depending on the length you want and how densely you knit. Look for a yarn with good stitch definition and some natural fibre content if possible — wool, alpaca, or a wool blend will give you the warmth and drape that works best with this construction. Pure acrylic works well too and is an excellent choice for anyone with wool sensitivities or for a gift where you are unsure about the recipient’s preferences.

Needles: 10mm to 12mm straight or circular needles. Because the scarf is long, many knitters prefer circular needles even for straight knitting, as the cable holds the stitches when the fabric becomes heavy. There is no actual knitting in the round here — you are simply using the circular needle as a long straight needle.

Additional tools: A tapestry needle for seaming and weaving in ends, stitch markers if you find them helpful for tracking your place, and scissors.

Gauge: Approximately 8 to 10 stitches per 10 centimetres in stockinette stitch on 10mm needles with bulky yarn. The double thick construction means exact gauge is less critical than in a fitted garment, but working a small swatch before you begin is always worth the time.

Understanding the Double Thick Construction

There are two main approaches to making a double thick scarf, and both are described here so you can choose the one that suits you best.

Method One: Knit flat and seam. This is the simplest approach. You knit two identical scarves — or one very long piece that you fold in half — and then seam the edges together, leaving the ends open or closing them as you prefer. The result is a clean, neat double layer. The seam runs along one long edge and is virtually invisible when done with matching yarn. This method is ideal if you are new to knitting or if you want complete control over the width and length of each layer.

Method Two: Double knitting. This is a more advanced technique in which you work both layers simultaneously on the same set of needles. You essentially work every stitch twice per row — once for the front layer and once for the back layer — alternating between knit and purl stitches across the row. The result is two interconnected layers that emerge from the needles already joined at the edges you choose to close. This method requires a bit more concentration but produces a structurally integrated fabric with no seaming required.

For this pattern, we will use Method One, which is accessible to knitters of all levels and produces a beautiful result with minimal technical complexity.

The Pattern

Finished Dimensions

Approximately 20 to 22 centimetres wide and 180 to 200 centimetres long (after doubling and seaming). These dimensions create a scarf long enough to wrap twice around an average adult neck with enough length left over to tuck or drape attractively.

Abbreviations

CO — cast on
K — knit
P — purl
RS — right side
WS — wrong side
BO — bind off (cast off)
Rep — repeat

Cast On

Using the long-tail cast on method, cast on 20 stitches. The long-tail cast on gives a neat, slightly elastic edge that works well for scarves because the ends will be visible and handled frequently.

If you prefer a wider scarf, cast on 24 or 28 stitches, keeping in mind that every 4 additional stitches in bulky yarn on 10mm needles adds approximately 4 to 5 centimetres to the width.

Stitch Pattern

This scarf uses a simple seed stitch border with a central knit panel, which creates a flat, reversible fabric that does not curl at the edges. This is essential for a scarf meant to be seen from both sides.

Row 1 (RS): K2, P2, K to last 4 sts, P2, K2.
Row 2 (WS): K2, P2, K to last 4 sts, P2, K2.

That is the entire pattern. Repeat Rows 1 and 2 until the piece measures approximately 180 to 200 centimetres from the cast on edge, or until you have used approximately half your yarn (since you will knit a second identical piece).

The two knit stitches at each edge give the scarf a clean, stable border. The two purl stitches inside the border create a subtle visual line that adds structure and definition. The central panel in stockinette-style knitting on both RS and WS rows actually creates a slight textural interest because the RS rows create a smooth knit surface while the WS rows show the purl bumps — this is intentional and gives the finished scarf a pleasing, slightly rustic texture.

Bind Off

When the piece reaches your desired length, bind off loosely using a standard knit bind off. If you tend to bind off tightly, go up one needle size for the bind off row. A tight bind off on a scarf creates an unpleasant rigid edge that is very noticeable in wear.

Leave a tail of approximately 30 to 40 centimetres for seaming.

Knit the Second Piece

Using the remaining yarn, cast on and work an identical second piece to exactly the same length. Use the row count from your first piece to ensure they match.

If you are very precise about matching length, you can place the first piece against the second as you knit and compare them side by side, measuring both at regular intervals.

Blocking

Before seaming, block both pieces. This step makes an enormous difference to the finished result. Wet blocking — soaking the pieces in cool water, pressing out the excess water gently without wringing, and then laying them flat to dry pinned to your preferred dimensions — evens out the stitches, opens up the fabric, and makes the seaming much easier and neater.

If you are using superwash wool or acrylic, you can also steam block by hovering a steam iron above the fabric without touching it. Never press an iron directly onto knitted fabric.

Allow both pieces to dry completely before proceeding.

Seaming

Place both pieces on a flat surface with their right sides facing outward and their wrong sides touching each other. Align the edges carefully, matching the cast on and bind off edges and the two long edges.

Using the mattress stitch and the long tail left from your bind off, seam the two long edges together. The mattress stitch is worked by picking up one bar between the edge stitches on one piece and the corresponding bar on the other piece, alternating between the two pieces and gently pulling the yarn to close the seam. When done correctly with matching yarn, the mattress stitch seam is virtually invisible.

Leave both short ends (the cast on and bind off edges) open. This creates a pocket-like tube through which cold air cannot pass, adding to the scarf’s warmth. If you prefer a completely closed construction, seam the short ends as well, but most knitters find the open ends easier to manage and equally warm in practice.

Weave in all ends securely using the tapestry needle.

Tips for a Beautiful Result

Consistency in tension matters more over a long project than it does over a short one. If your tension changes significantly from the beginning to the end of your knitting session, those changes accumulate over the length of the scarf and become visible. Try to knit in similar conditions — same posture, similar level of relaxation — throughout the project. If you are a noticeably tighter knitter when you first pick up your needles, work a few rows at the start of each session before the main project to warm up your hands.

Yarn choice has a significant impact on the drape and overall feel of the finished scarf. Very springy wools can make the scarf feel slightly stiff or bouncy; they work best with a slightly larger needle than the label suggests. Alpaca and alpaca blends are very drapey and luxurious but can grow in length over time due to their weight. Mohair adds incredible softness and a halo effect but can be challenging to unknit if you make a mistake. For a first attempt, a straightforward smooth wool or wool-acrylic blend is usually the most forgiving.

Colour selection is a personal decision, but there are a few considerations worth keeping in mind. Heathered or tweed yarns are extremely forgiving of minor tension inconsistencies because the visual texture disguises them. Solid colours showcase the stitch pattern most clearly. Gradients and self-striping yarns can produce unexpectedly beautiful results in a long scarf because you get to watch the colour story unfold over the full length of the project.

Customisation Ideas

Once you have made the basic pattern once, there are many ways to modify it for different results.

Add stripes. Because both layers are knitted separately, you can easily stripe them differently, creating a scarf that has one colour on one side when it folds over. Use contrasting colours for a bold look, or tonal relatives for something more subtle.

Change the stitch pattern. Replace the central stockinette panel with a simple cable, a rib, or a moss stitch for different textures. Keep the seed stitch or garter stitch border to maintain the flat edges regardless of what you do in the centre.

Adjust the width. A narrower scarf of 15 centimetres or so is sleeker and more contemporary. A wider scarf of 25 to 30 centimetres becomes more of a wrap or cowl alternative. Adjust your cast on number accordingly.

Add fringe. Even though this is a double thick scarf, you can add fringe to the open ends by cutting lengths of yarn, folding them in half, and pulling the folded loop through the edge stitches with a crochet hook. Fringe adds movement and can be trimmed to any length.

Caring for Your Scarf

Proper care keeps your double thick kilometre scarf looking beautiful for years. For wool and wool blend scarves, hand wash in cool water with a gentle wool wash product, press out the water without wringing, and lay flat to dry. Most wool scarves should not be hung to dry as the weight of the wet yarn can stretch the fabric significantly.

For acrylic or superwash wool, check the yarn label for machine wash instructions. Many modern superwash wools and quality acrylics can go in the machine on a gentle or delicates cycle in a mesh laundry bag.

Store knitted accessories loosely folded rather than compressed in a tight drawer or bin. If storing wool for a season, add cedar blocks or lavender sachets to deter moths.

A Pattern Worth Making More Than Once

The double thick kilometre scarf sits in that rare category of patterns that are genuinely worth revisiting. It is long enough to feel like a commitment but straightforward enough that you will finish it. It is warm and practical but beautiful enough to wear somewhere nice. It is simple enough for a beginner but engaging enough that experienced knitters do not find it boring.

Make one for yourself in a colour you love and give yourself permission to wear it constantly. Then make one as a gift — there are few handmade items more appreciated than a beautifully made, generously proportioned winter scarf. Then experiment with the stitch pattern, the yarn, the colour, and discover how different each version can look while following essentially the same instructions.

This is knitting at its most accessible and most satisfying: an honest, useful, beautiful thing made by hand, one stitch at a time.

Happy knitting.