Missing instructions on knitting pattern!

Just measure it against said toddler or a garment already in use?

Try google. I've found the youtube type knitting sites a god send since I started knitting again. I've found patterns less helpful. I've just finished a huge cardigan (Mr Iam is not small) and the instructions for adding the rib to include button holes said simply, pick up and knit 390 stitches around the edge (having sewn the shoulder seems together of course). There was no reference to the need to use a circular needle. Had I never knitted before I think I'd have lost the will to live at this point. Google became my friend.

Witzend Hugely frustrating, of course, but have you ever tried to proof-read a knitting pattern? Actually, there are professional pattern checkers who read the pattern and mentally knit it. I am all admiration as I can imagine few jobs I'd like less. Perhaps the company that produced the pattern is too penny pinching to pay for this remarkable skill.

This sounds familiar! My friend recently knitted a baby cardigan with hood, and got to a point of the instructions that sound exactly like yours. After a lot of frustration on her part, she eventually asked for help and down I trotted. After rereading the pattern several times and lots of tea and biscuits we eventually worked out that after you had knitted what looked like a rectangle and being told to cast off... that you were meant to then fold the cast off edge in half and sew it up ! Thereby getting a hood shape!
The picture was useless as there was no view of the top of the hood, could your pattern be the same ?

Someone must have knitted the pattern as a test though, as there is usually a picture on the front.

I couldn't knit it mentally!

I have a Patons cardie pattern which has a hood, I could have a look.
It is knitted in DK on size 4mm needles and the sizes are:
1-2, 2-3, 4-5, 6-7 years

age 1-2 - knit until hood measures 15cms (6")
age 2-3 - 16cms (6.25")
age 4-5 - 17cms (6.5")
age 6-7 - 18cms (7")

Then you start to shape the back of the hood which takes another 10 rows.

The pattern is Patons P1027 if you want a comparison

sorry, it's a Peter Pan pattern and it doesn't show the hood but here's a picture

Quick thought, could you go on pattern website, search for the pattern and see if they have added any pattern corrections.

Phew, there was an answer to my email the same day! Error had already been noticed and an amendment issued.
But thanks so much for replies and help, everybody.
I'm not the most expert knitter in the world, so not at all confident of making correct guesses - I purposely chose a relatively simple pattern that I'm not likely to mess up.

Iam64, I did once lose the will to,live over 'pick up and knit' the edging band for a big slouch cardi I was supposed to be knitting for my sister. The yarn was black, so hard to see the sts anyway, and after multiple attempts and a lot of swearing and frustration, I abandoned the bl**dy thing. Luckily the yarn was not expensive!

There is some pick up and knit on this one, but it's very minor and the yarn isn't black. But I will check YouTube anyway, thanks for the tip!