This question has been coming up a lot recently – some ladies at the knit night, my own hat adventures, and even in email, so I thought I would post the formula that I use for it.
Step 1 – Multiply the number of stitches you need to decrease by 2 – because each decrease uses up two stitches. If your decrease uses 3 stitches (k3tog, or slip1, k2tog, psso for example) then you multiply by three, and so forth.
Step 2 – Subtract that number from your total number of stitches. This gives you the number of stitches that your decreases will need to be space over; ie, all the stitches that won’t be used in the decreases.
Step 3 – Divide the number of stitches not used in your decreases by the number of stitches you need to decrease.
Step 4 — if it is really important to place the first and last decreases equidistant from the ends of the row (if something is being worked in the round, or will be seamed round), divide the step 3 number by two — this tells you how many stitches to knit from the beginning of the round before the first increase.
Here is is written as formula –
Step 1 – total stitches – (decreases x number of stitches used in decrease, usually 2) = stitches not used in decreasing — this is steps 1 and 2 from above.
Step 2 – stitches not used in decreasing / decreases = stitches to knit between decreases
Step 3 – stitches knit between decreases / 2 = stitches to knit before first decrease from beginning of row.
And here is a sample:
If I have 54 stitches, and I need to decrease 3 evenly over one round, first I multiply 3×2 — which gives me 6. (Step 1)
54 minus 6 gives me 48. This is how many stitches that will be left after the decreases. (Step 2)
Then I divide 48 by 3 — which gives me 16, the number of stitches to knit between each decrease. (Step 3)
I’m working in the round though, and want to space evenly from the beginning of my row — so I divide 16 by 2 — which gives me 8. (Step 4)
To knit the round, I’ll k8, k2tog, k 16, k2tog, k16, k2tog, k8 – leaving 51 total stitches. A successful decrease of three, evenly distributed around.
The main problem you will run into is fractional numbers , which in knitting terms means extra stitches. Just fudge it — slide the extra stitches in as evenly as possible, maybe on opposite sides of your piece, or if the pattern allows it, maybe work a k3tog instead of a k2tog to even them out.
Lagniappe: You can also use step two of the formula to space increases evenly. It varies slightly for increases worked in between stitches (YO, lifted bar increases) and increases worked in a stitch (Kfb is the only one I can recall right now)
Those formulas written independently are
For increases between stitches: total stitches / number of increases = stitches to work between each increase,
and for increases in stitches: (total stitches-number of increases) / number of increases = stitches to work between each increase.
Ow! (flinches and hides eyes behind fists) You just gave me a headache.
(And a useful technique. Thank you!)
Yeah, that headache. Two aspirin, hot tea, avoid socks with calf shaping and making up your own hat patterns.
At least it’s all finally written down, and I/we won’t have to re-figure it out every time now.
So….I am making a hat, 80 sts as follows: p2,c4,p2,k1,p2,t2,p2,k1….I am seriously confused as how to decrease with out totally loosing the pattern. Anyone??
Amazing technique! I’m completely new to “decreasing evenly” and just tried this method on my first ever socks and it worked brilliantly! Thanks!!!
Hi! I was surfing and found your blog post… nice! I love your blog. 🙂 Cheers! Sandra. R.
i don’t get how this is working for you guys. The directions involve subtraction, and the example requires division. Neither formula seems to work for me.
I, too, appreciate the formula, but I agree with Cat’s post. There is an error in the original post. Step 3 tells you to “Subtract the number of decreases (not the multiplied number) from the number of stitches that you aren’t using to decrease. This gives you the number of stitches to knit between each decrease.” I believe that you meant to direct us to “divide the number of stitches you aren’t using” by “the original number of decreases.” When I tried my own example with the original directions (90 st with 13 st dec), I would have 51 stitches between decreases! However, dividing such as in your example (not instructions), I got 4.9 stitches which seems more logical.
You are both right — I finally got around to going over this in detail, and I messed it up. I’m fixing it now.
You are right! I’ll correct that.
Do you decrease in the beginning,middle or end of the piece?
when doing a sleeve do you knit say 8 rows decrease by one knit 8 rows then decrease by 2 ? and then do you knit 7 rows decrease by 3 repeat it then knit 6 rows and decrease by 4 and so on ? am i right in thinking this is how to do it or am i wrong? I am a novice so please be gentle with me.
Decreases can be at the beginning, middle or end of your row — or in all three places at once — it depends on how many stitches you are trying to decrease, and what the decreases are being used for.
For something that tapers, like a sleeve or the top of a hat, there is usually a decrease row, a plain knit row, and then another decrease row. Each decrease row will usually have a pattern like k2, k2tog all the way around. If I knew more about what precisely you were working on, I might be able to answer your question more specifically.
Here is a sample of what a decreasing section of a pattern might look like:
row 1 – knit around row 2 – knit 5, knit two together, repeat until end of row row 3 – knit around row 4 – knit around row 5 – knit 4, knit two together, repeat until end of row.
This would shape a piece of fabric with a gentle taper from wide to narrow.
I hope this helps, and please let me know if I’ve explained things well enough!
Hi Anna, What a great explination. I too picked up your error just in reading it through but I’ll admit that I am a bit of a Math whizz….I have been knitting for about ten years now and the only reason that this is peculiar (to some) is because I am a man. i love knitting! I make sculptural creations and have a thing for obscure stuffed toys. having a mind for mathematics has helped me alot in knitting and if your readers, and other knitters, would realise their knitting as a math problem (not a “problem”) then they will find that increases and decreases become a breeze…Thank you for taking the time to explain a complicated issue….regards, Leon