When a pattern tells us to evenly increase or decrease stitches in a row, that means that we have to do some basic math to figure out how many stitches we should leave between the increases / decreases and how to make sure those increases / decreases are more or less centred, so that the knitted piece looks symmetrical.
It’s a bit inconvenient but definitely not a complicated task. In this tutorial, I’ll show you the method I use when I see instructions similar to the ones highlighted in this photo:
To make things easier, let’s break down the process of “evenly increasing or decreasing stitches” into two parts. In the first part, we’ll divide all stitches into even segments and make sure those segments are centred within the knitted piece. In the second part, we’ll get to actually increase or decrease stitches.
This part requires making a few simple calculations. As you see from the photo above, the sample pattern tells us to evenly decrease 10 stitches in one row to bring the number of stitches from 80 to 70.
1.1. DIVIDING STITCHES INTO EVEN SEGMENTS
The first thing to do is to divide the number of stitches we have on the needles by the number of decreases plus one. In our example, that would mean:
80 stitches / (10+1) = 7.27 (approximately)
You might wonder why we add 1 to the number of decreases. It is a little trick to make sure the decreases are centred. If we divide the number of stitches by the number of increases / decreases we have to make, the last increase / decrease will be at the very end of the row. That will distort one of the sides of the fabric, and the knitted piece won’t look symmetrical.
To better understand this concept, take a look at the chart below. The stitches between the increases/decreases are marked with dashes, and the increases/decreases are marked with dots.
As you see, we only get a symmetrical spacing when we have one extra segment of stitches.
Now, that we have this issue settled, let’s get back to the process of increasing / decreasing stitches evenly.
NOTE: All of the above is only relevant for increasing/decreasing evenly within a row. If you work in the round, there is no need to add an extra segment. Simply divide the number of stitches by the number of increases/decreases you plan to make.
1.2. CENTRING THE SEGMENTS
If the result of your first calculation is a number without a remainder, you are in luck, and you can skip this step and confidently move to Part 2.
But in the majority of cases, the result of the first calculation will be a number with a remainder, just like the calculation in our example: 80 / (10+1) = 7.27 (approximately).
Of course, we can round this number down and increase/decrease stitches within every 7 stitches. But the extra 0.27 pieces will add up, and depending on the number of segments in the project, those little bits can turn into quite a few stitches.
If we don’t account for them, our increases/decreases will be gathered in the first part of the row, and the knitted piece will be asymmetrical. It affects the look of the fabric, but most importantly, it can distort the fit of the finished project.
To avoid that, we need to make a few additional simple calculations.
(a) First, let’s figure out how many extra stitches we are going to get. Multiply the whole number of the stitches in a segment by the number of segments. In our example it will be:
7 x (10+1) = 77 stitches
Then, subtract this number from the original number of stitches:
80 – 77 = 3 stitches
That means that those 0.27 bits of stitches will add up to 3 stitches. Not that bad, but if we had a few hundred stitches on the needles, that number would be higher and the fabric distortion more substantial.
(b) Now, let’s divide those extra stitches by two and add half of them to one side of the fabric, and the other half to the other side.
Because we can’t divide 3 by 2 without a remainder (and we can’t work 1.5 stitches), let’s assign two stitches to the beginning of the row and one stitch to the end of the row.
Here’s the distribution of stitches we get as a result:
2 extra stitches + [7 stitch segment], work brackets 10 times + an extra 7 stitch segment + 1 extra stitch = 80 stitches
NOTE: If it is mathematically correct to round the result of the first calculation up (for example, if we get 7.72 instead of 7.27), then we have two options.
The easier but less precise way is to find out the number of extra stitches and work half of them at the beginning of the row, and the other half at the end of the row, just as we did in our example. That will result in wider segments at the sides of the work, but it won’t distort the look and the shaping of the fabric.
The more precise way will be to spread those extra stitches between segments. In our example, we would alternate segments of 7 stitches with segments of 8 stitches. This option requires more tedious calculations, and I won’t cover it in this tutorial to keep the things as simple as possible.
Now, that we have our stitches more or less evenly segmented, it’s time to make increases or decreases.
After all the math that we’ve just been through, this part is going to be easy.
To increase stitches, add a new stitch after each segment of stitches (except the “extra segment”).
In our example, it will look like this:
work 2 stitches + [work 7 stitches, increase], work brackets 10 times + work 7 stitches + work 1 stitch = 90 stitches
Feel free to use any type of increase – a yarn over, a “make 1” increase, or any other way to add a new stitch to the project recommended in the pattern you follow.
To decrease stitches, work to the last two stitches of each segment (except the “extra segment”), then knit 2 stitches together, work an SSK decrease or decrease one stitch in any other way you like.
In our example, we’ll work as follows:
work 2 stitches + [work 5 stitches, decrease], work brackets 10 times + work 7 stitches + work 1 stitch = 70 stitches
In fact, this example comes from a pattern for a project I’m working on right now (Lou Sweater by Phidar). I used these same calculations to decrease stitches when I transitioned from the ribbing to the main pattern and got 10 evenly spaced decreases.
I hope this tutorial will help you evenly increase or decrease stitches in your projects to make perfectly symmetrical well-fitting knits. Happy knitting 🙂
If you enjoyed this tutorial,
here’s something else you might find helpful:
“Neat Side Edges” Book
Learn twelve ways to make side edges of a knitted project nice and tidy. Plus, ways to fix side edges, and a way to improve edges of finished projects.