Hello 
I’ve recently tried my first knitting-in-the-round-project, the Zombie Slouch Beret by bibleapologetic.blogspot ( sorry I couldn’t post the link) and my hat comes out too small. I’ve only knitted the first few rows of the rimming before trying it on my head and realised that it is way too small, a bit like a child hat. I’m using 6.5mm DPNs as stated in the pattern but I’m using a different type of yarn. Is there any way to calculate the number of extra stitches I’ll have to make to make the hat bigger? Thanks in advance
Oh sure. Make a gauge swatch by casting on ~24sts (or some estimate that will give you about 5 inches knit up), knit for about 4 inches and measure how many sts you get over the center 4 inches of stockinette stitch with your yarn and needles. The pattern is worked at 12.5sts/4inches. Once you know your gauge you can calculate how many more sts you would need to cast on to get the same dimensions as the pattern.
You don’t really need to do a separate swatch, measure the sts per inch you got in what you knit so far, then follow the instructions salmonmac gave.
It’s very hard to tell whether the hat will be the wrong size when you’ve only done a few rows. I find that it seems to look and be so much bigger after I’m further into it. Plus, measuring it on your head while still on DPN is not a good way to tell. The needles are too restricting and the yarn can’t stretch to properly.
Ribbing naturally pulls in, but it needs a good inch to really show well. Ribbed hats therefore look really small because of the stitch, but they stretch to full size.
All that being said…if you use a smaller gauge yarn then it might very well be too small. The pattern calls for bulky. What did you use?
Thank you so much! :yay: I’ll try it immediately 
So, if I need 20 stitches to make 4 inches I should just add 7.5 stitches for every 12.5 stitches, right?
Haha A SHORTCUT!!! Thank you for sharing this with me 
Ahh… I see… Thank you for posting the link I couldn’t post it because of my lack of posts!! Should I continue with the hat then? Just to see how big it turns out ? My yarn is more of a 5 or 6 needle size yarn. Is that bulky? It was certainly the bulkiest yarn I could find at my local knitting store 
Yes, that’s what you would do if you decide to go with the stockinette st swatch. If you use the ribbing to measure gauge, slightle stretch it, see how many sts per 4 inches and figure out how many you would cast on for 1-2inches smaller than your head circumference.
What yarn are you using?
Okay, here’s some things that could be going on. What type of yarn are you substituting? If the pattern calls for a worsted weight and you’re using a sport weight, your hat will be too small. You will have to adjust your numbers like the previous posters said to do.
If your weights are the same, the pattern calls for a #4 worsted weight of one brand and you’re using a #4 of another brand, you should be okay. There is a weight number on the yarn label.
But I suspect that what is happening is not you, your yarn, or your knitting but the cast on. The wrong cast on will make this hat appear too small, but there’s nothing wrong with the body. Just the edge.
I knit a beautiful pair of mittens for a child. I used a long tail cast on for the cuff. Even casting on loosely, it was so tight that she couldn’t get her hand in the mitten! I learned my lesson after that. For all my hats, mittens, and gloves, I now use the German Twisted cast on. This stretches as far as the yarn will allow, but quickly snaps back to shape. KH has a video on how to do it here. I think using this cast on will solve your problem. Let us know how you make out.
http://www.knittinghelp.com/video/play/german-twisted-cast-on
Your yarn wrapper will say what weight it is or at least give you the gauge. Bulky/chunky yarn will have a number 5 on it. Here, check out this page of standard yarn wights and gauges. What is the name of your yarn.
http://www.craftyarncouncil.com/weight.html