How can I resize this crocheted hat pattern for an infant? I want to make an infant-sized version of this hat (PDF).

The current pattern (assuming correct gauge) makes a hat with an 18.5" (47cm) circumference. It seems that a common size for a newborn/infant hat is around 12.5" (32cm), which is about 1/3 smaller.

The pattern calls for  using a 6.5 mm crochet hook but I'd like to use the same size hook that I'm already using (for the blanket) which is a 5 mm hook. To make this slightly more confusing, the "materials" section calls for a 6.5 mm hook but the "gauge" section calls for 6 mm, so I'm not sure which of the two is actually correct.

The pattern gauge is:
13 stitches and 11 rows = 4" (10 cm) with a 6 mm hook

The yarn I'm using has the following factory gauge info:
18 stitches = 4" (10 cm) with a 5 mm hook

Given this info (and assuming I crochet perfectly on gauge), do I actually need to adjust the pattern at all or is the hook size/yarn difference sufficient to make it small enough?

If I do need to adjust the pattern, the following info may be useful:


The hat is worked in rounds from the brim to the top.
Each of the first 19 rounds consists of 50 stitches, grouped in 5s, so 10 repeats.


The decrease rows are where my main concerns lie. It's simple to reduce the main rounds by 5 or 10 or 15 stitches to make the circumference smaller but I'm not sure how this will affect the decreases at the top of the hat.

For balance, it seems like I may also need to reduce the number of rounds but, again, this may depend on whether the hook change is sufficient to reduce the size or not.
First of all, you need to figure out your gauge (sts &amp; rows) using your #5 hook and the yarn you want. Using your baby inches, see how far off you are from the pattern. Use that as a rough ruler for following the pattern. You'll need to keep to an even or odd # of sts in your baby length, but also notice the group sts and how many sts they take each so you'll have the right # of sts to work into. Does that make sense?

To begin with, I would suggest you reduce the # of rows in the band, so it won't be 1/2 of the hat unless you want to make a cuff with it. You'll have to keep track of the rows so you'll know when to start a new one and when to decrease. 

I can't tell you exactly how to decrease without dealing with the pattern and your gauge. I suggest you see how the first several rows after the band shape up and look at how often the pattern suggests dec. It's not the end of the world if you have to take out a row or 3. It should be pretty quick work; it's not a complicated pattern.

I hope this has been some help. When I increment or decrement a pattern, I just have to wing it beyond a certain point. As I said, taking out some rows won't take long to re-do.