Worsted weight yarns and aran weight yarns are often thought to be interchangeable, but they’re actually different yarn weights.
While they’re both considered medium weight yarns, worsted yarn is finer than aran weight yarn. Worsted yarn is often knit on 4.5mm needles with a gauge of 4.5-5 stitches per inch.
Aran weight yarn is thicker and often loftier than worsted yarn. It’s often knit on 5mm needles with a gauge between 4-4.5 stitches per inch.
To make matters more confusing, aran yarn is sometimes called “heavy worsted” or “10-ply yarn.”
Another consideration is that in the UK, the term “aran” is more widely used than “worsted” to refer to medium weight yarns. So, a worsted yarn may be categorised as aran weight in the UK.
For this reason, if you’re using a UK knitting pattern, consider trying worsted weight yarns even if the pattern calls for aran weight.
Can You Substitute Aran for Worsted Weight Yarn?
While both worsted and aran yarn are in the medium yarn weight category, they have slight differences.
An aran weight is generally heavier than worsted weight yarn, resulting in a smaller gauge. For instance, an aran yarn may have a gauge of 16 sts = 4” while worsted yarn could have a gauge of 18 sts = 4”.
This difference may not seem like a big deal, but if you’re knitting a large number of stitches, the two-stitch difference will start to compound.
For instance, let’s say a baby blanket pattern calls for worsted weight yarn with a gauge of 18 sts = 4”.
The pattern requires casting on 200 stitches. Using the correct gauge, the finished measurement will be 44.5”.
Let’s say you’re looking to substitute aran yarn with a gauge of 16 sts = 4”
Using aran yarn, the blanket will be larger than the pattern’s finished measurements. Because of the gauge difference, it will be 50” instead of 44.5”. That’s almost a 12% difference!
For items like blankets, sizing may not matter very much. But when it comes to garments or accessories for the body, a few inches is the difference between one or two dress sizes.
Ultimately, the best way to decide on yarn for a pattern is to swatch the yarn. Ensure that your gauge matches the pattern’s gauge, troubleshooting with different sized needles or yarn weights if needed. The other option is to re-work the pattern to fit the gauge you have.
What is Worsted Yarn Used For?
Medium weight yarns like worsted and aran yarns are the most popular among knitters. It’s not hard to see why!
These yarns knit up quickly and provide both warmth and drape. Worsted and aran weight yarns are ideal for garments like sweaters and cardigans as well as accessories like scarves and mittens and home decor like pillows and blankets.
Worsted and aran are true all-purpose yarns!
Favorite Worsted and Aran Yarns
I’ve worked with a lot of medium-weight yarns in my time, and I have a few firm favorites. Allow me to share them with you!
Malabrigo Worsted is my go-to choice for single-ply worsted yarn. Spun with Uruguayan merino, it’s as soft as a cloud and a total joy to knit with. The yarn is kettle-dyed in beautiful tonal and variegated colors. This is the iconic yarn that started my love affair with Malabrigo. 10/10 would recommend!
Debbie Bliss Cashmerino Aran combines super soft merino with the lusciousness of cashmere. It’s gentle on the hands and glides through needles like a dream. This gorgeous yarn is machine-washable and comes in a range of beautiful colors, from pretty pastel pink to deep charcoal and rich aquamarine.
Sheep and Stitch’s Classic Beanie is knit in Debbie Bliss Cashmerino Aran in Burnt Orange.
My favourite budget-friendly worsted yarn is Knit Picks Swish Worsted. Spun in fine superwash merino, it’s super soft, machine washable and comes in a large selection of colors.
Rosemarie Bellone says
Hi, Divina! I am 63 years old and I have just started learning how to knit as a true beginner. I find your website extremely helpful and your videos very easy to understand and to follow. I do have one comment, however, and that is as far as your section regarding knitting needles. What you have not said is that the needles come in two sizes on each package and when you say 5 mm or 5.5 mm, do you mean the European size or The US size??? The package will only say number 10 or number 12 with the millimeter size underneath but I am not sure whether you mean the European size or the US size. Please keep your videos coming because I have learned more from your website then I actually did with a teacher in a live class!
tova shpantzer says
For the scarf for beginners I heard we need needles #10, but It difficult to hear ghe kind if yarn you recommen.
Can you write the yarn and needles, please?
Maurinne Sombillo says
Hello ms divina, i am mau from philippines, i am a total beginner and your tutorials in youtube made me 0 to level 1 or level 2 i think 🥰, i bought yarn in an online app and i dont have any idea about the size of the yarn, the only description in here is
Yarn count: 8 ply
Yarn Diameter: About 3mm (0.12 inch)
I only have limited kind of needle and 1 size of yarn, i have 8.0, 6.0, 5.5mm of needle.
I made a hat thats in your tutorial using 5.5mm and it turned out small, then i saw your GAUGE video and learn many things, my only problem is the size of the yarn..
Thank you for all your works it helps me clear my mind 🥰
Terry Mendola says
I weave (beginner) on a Schacht Rigid Heddle Loom. If I want to purchase yarn and am trying to figure my ends per inch, is there a way to calculate prior to purchasing? Would it be safe to use the stitches as my guide? Hope this makes sense!
Unless the shop allows you to swatch with un-purchased yarn, you’ll need to go with the yarn tag’s gauge suggestion. And then play around with the gauge by using different needle sizes.