Here's my current WIP with it's buttons, just because every post needs a pretty photo
Anywho, the question I've been asked the most lately is what size people should knit if they want to cast on in 12ply etc. I had been looking at this myself as I'm planning on knitting a Young Einstein in 12ply for my 2 year old as a hooded jacket.
To work it out, you must know the gauge of the yarn and needle combination you are wanting to use. There's no way to work it out otherwise - don't just assume that the ball band suggestion for your yarn will come out right either!
So you might want to do a gauge swatch first. If you're a bit eager to start (like I often am), you might just start knitting the pattern but be prepared to have to rip it all back if your gauge is out when you check it.
Right, then the calculating.
So, you take your gauge, for example 16 stitches per 10cm/4inches. What you need to know to work this out is your gauge for 1 inch. So take your 10 stitch gauge and divide by 4
eg 16/4 = 4. So, in 1 inch, you'd have 4 stitches.
Then, you need to look at what size you are planning to knit, and here it helps to know a little bit more about the 'ease' in the pattern. My pattern is written with 3" of positive ease. So, a 22" chest has 25" in the pattern (this is to give it enough room to move about easily in and fit some warm layers underneath during winter). Take the size chest you are wanting to knit and add 3 (the inches of ease) to it.
Take your gauge inch (from my example it was 4) and times it by the total number of inches for the chest size (my other example was 25")
4 x 25 = 100
That '100' is the number of stitches you want when you are knitting the chest.
Regardless of whether you are wanting to knit a Hoodlum, Hotshot or Young Einstein, you now need to look on the left hand side of page 8 in the pattern. Above the astericks, there is a paragraph that says:
"You should now have...stitches"
Have a look in there and find the same number as you've calculated. I can see that my 100 stitches is there in the brown writing, the 3rd size in the pattern. I'd then double check with the info on page 3, and that tells me that I'm going to knit the 3-6 months/17" size pattern in 12ply, with my 16st gauge to get the right chest size for the 22" child I have. You then knit to the lengths in the pattern for the age of your child for the body, sleeves and hood.
If you can't find your number, it's because the size you are wanting to knit falls between the sizes in my pattern. That's when you decide whether you want to knit the size above or below it. And, just a head's up, with a 16 stitch gauge, the smallest size you can knit using my pattern is a 20" - which works out to the newborn in my pattern.
Now, this is all just a bit of easy calculating...it doesn't take into account the length of the raglan and so this is just if you want to give it a go. I've yet to try it myself, so can't tell you whether or not it makes the V too long for the hoodlum/hotshot or the arms too deep or anything...so if it works out looking terrible, I take no responsibility for it! But if it works out great, I'd love to see it on Rav!