It's a fairly common experience to fall in love with a pattern, but feel that the finished object isn't quite what you were looking for. Maybe you want to use a particular yarn in stash that isn't the right weight, or perhaps you don't really want a DK weight sweater, or you think a lace pattern would look fantastic in worsted weight. So what do you do? It really depends on your comfort level in modifying patterns, as well as the strength of your desire for the object you are envisioning! It is completely possible to change the gauge of a pattern, sometimes quite radically, but there are a few things to consider in order to be sure that you will love the finished object. I recently discovered the Wayne pullover by Sari Nordlund, a stunning cabled pullover knit in DK weight yarn. But I had a sweater quantity of grey fingering weight that I wanted to use up, and I thought it wouldn't be that difficult to substitute. I was right! My finished fingering weight Wayne is lovely to wear, and I think the smaller cables look fantastic.
[Image Description: A photograph of a white woman from shoulder to hip, wearing a grey cabled sweater, with her hands resting in her lap. Her right shoulder is angled towards the camera, showing the details of the cables running down the sleeve and the front and back panels of the sweater. Her dark brown wavy hair is cascading over her left shoulder.]
So once you have a pattern and a yarn, what do you do next? Firstly, and most importantly, you need to knit a large gauge swatch with the yarn you intend on using (maybe even knit several!). Wash and block it in the same way you intend to launder the finished object (steaming, washing on the wool cycle of your washing machine, etc) - check out my blog post on swatches and measuring gauge for more details on how I swatch. Then take your time, play with the swatch, and consider the fabric characteristics and how well they fit the actual pattern. If you want to knit a very drapey summer shell, you need to play around with the new yarn to be sure it produces a drapey fabric. Both fibre content and gauge will affect drape, so if you are finding the fabric is too stiff, then go up a needle size or two and try again! You will have more luck sticking with the same fibre, or something with similar characteristics. Wool has a lot of elasticity, and silk doesn't. Linen is light and crisp, and can be easily substituted with cotton, but not necessarily acrylic or alpaca. It is also fine to completely alter the characteristics of the fabric, as long as you feel confident that you will end up with something you love in the end. The more you experiment, the more you will learn.
[Image Description: A photograph of the collar and left shoulder of a medium grey cabled sweater. The central panel of the sweater is moss stitch, while the side panel is made up of four columns of different styles of cables.]
Once you have decided on a gauge, the next step involves some math and some thinking. Let's use my Wayne pullover as an example. The pattern gauge is 21 sts x 30 rows for 10 cm/4 inches, while the gauge of my fabric is 26 sts x 35 rows for 10 cm/4 inches (both of these are in Moss stitch). As is to be expected, knitting with smaller yarn and needles produces more rows and stitches per cm/inch. For the purpose of this discussion, the needle sizes are not relevant, other than to say that I am happy with the fabric produced. The pattern suggests 2-4 inches (5-10 cm) of positive ease, and my bust measurement is 34 inches (from here on, I will work only in inches to simplify the math, but it is all the exact same process with cm). I can't recall exactly how many inches of ease I chose when I originally made this garment, but for today let's go with 2 inches. That means I need to cast on enough stitches to have a measurement of 36 inches at the bust. The Wayne pullover is knit bottom up with no waist shaping, which makes things a bit easier - I can just compare to the cast on number once I've calculated how many stitches I need at the bust, whereas if there was waist shaping, I would need to do a bit more work to determine the stitch count at the bust to choose what size to knit. If I look at stitch gauge only, I can set up the following equation:
If you are comfortable with algebra, then this equation is fairly trivial to solve, but if not, not to worry! You need to isolate X, which in this case is done by multiplying both sides by 36. You will be left with the following:
This reduces to X = 234, meaning that I will need to cast on 234 stitches at my gauge in order to have a sweater with 2 inches of positive ease at the bust. When I look at the pattern, the two closest cast on numbers are 220 and 240. In this case, 240 stitches is the better choice, as the pattern recommends 2-4 inches of positive ease, so it would be better to err on the side of being a bit bigger than my calculation. Voila! Now I can be confident that despite using a different weight yarn, I will end up with a sweater that fits well and has a nice fabric.
This process can be intimidating at first, but the trick is to go slowly and carefully, step by step. It's also a good idea to check your final numbers afterwards to see if they make sense. In this case, the 240 cast on number corresponds to the 40 inch bust size, which would be reduced in size by my tighter gauge. So logically, this seems to be the right size. I can also do a quick check of my final bust measurement for 240 stitches at 26 sts/4 inches, which produces a diameter of 37 inches. This would give me 3 inches of positive ease, which is perfect. If you are using this post to make adjustments to a garment pattern, feel free to post a comment if you need help!
Have you ever changed the gauge of a garment or other pattern? Do you do it differently? Let me know!