What happen if you use wrong size of needle?

Most of yarn wrap seems to have what size of needle I am supposed to use for that yarn…
Does it really matter? What happen if I use too big or too small size of needle?

For example, I have size 7,9,10 needle … and new yarn says I need to use size 8… Do I really need to buy another needle just for this yarn?

The needle size on the ball band is a recommendation. It is the appropriate needle size for that yarn. What you need to watch is not necessarily the needle size, but rather the gauge listed in the pattern you are making. If you don’t get the proper gauge, it could make a BIG difference. It could mean a sweater that’s way too tight, or way too wide. Gauge is adjusted by going up or down in needle size.

That said, if you’re making something like a blanket or a scarf, then the needle size isn’t as crucial. It doesn’t need to fit.

But for anything like sweaters, socks, mittens/gloves, and hats to some extent, needle size and gauge are very important.

You mostly go by the needle size recommended by a pattern, but everyone knits at different tensions. If the pattern calls for 8s, you could probably substitute the 7s or 9s, depending on how close one of them is to the stitch gauge. Or you can make the next size larger or smaller. I use different size needles than what’s suggested all the time and like how my sweaters, etc turn out.


With the same wool, bigger needles will give bigger stitches, and a looser fabric. Smaller needles will give smaller stitches, and a tighter, warmer, denser, harder-wearing fabric. The needle size is probably what an average knitter would use to get the gauge (which is x stitches per 10 cm/4in). Some people knit tightly, and they need a bigger needle to get the same size.
Some people knit loosely, so their stitches are bigger, and they would need a smaller needle to get that stitch size. On the recommended needles knit a 6 in. square - of stocking stitch , unless the gauge/tension part of the label states otherwise - and measure your stitch number over 4 in. in the middle. If you get more stitches than the label says, you are a tight knitter, and need to use a slightly bigger needle to get gauge.

The label gauge is what the manufacturer thinks is necessary to get the best fabric: not too stiff, drapes nicely, but not holey. You might want to change it: for socks, you normally knit tighter than recommended because you don’t want nice drape and you do want good wear. Or if you’re doing lace, you might want a bigger needle to get net-like fabric. I say do a tension square with 7s and another one with the 9s, decide which fabric you like best. Make sure you wash the square the way you normally will with the knitted item first. Make sure you know which one’s the 7s, and which the 9s.
Which one gives the best fabric for the item you are going to make? Go with that.
You only need the 8s for this if you think ‘the square knitted on the 7s is too loose and floppy and net-like, but the square done on 9s is too tight/dense/etc, right in between would be perfect!’.


I think you’ve got those reversed - 7s would give denser stitches than 9s…

But essentially, the rest of your advice is correct, though I thought the label gauges are also what defines the `weight’ of the yarn, as in DK, worsted, etc…


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I am working on a lace capelet which requires 58 rows using an 8 needle, then moving to 28 rows of the same pattern in size 7. I have just finished the first 58 and find I have used the a 7 instead of an 8 - what do I do?

Keep going or just use a 9. The gauge probably isn’t that far off that it would matter, especially a lacey item. It may be a little larger, but then don’t stretch it as much if that would make it too big.

Thanks for the help, but I’m not sure I understand your answer. The first 58 rows of the body were to be done in size 8, then the last 28 rows in a size 7 (I guess to shape it slightly), the I need to do the edging separately in a size 8 and attach. Should I continue with the body in 7 and then just move to the 8 for the edging? You kind of through me off when you mentioned a nine? Thanks, Leslie

Some patterns reflect the individual knitting gauge of the pattern designer. For me, I knit loosely so I have to go down one size. If you knit tightly, you may have to go up one. This is why it’s important to knit a gauge swatch to see what you get and adjust your cast on stitches or needle size accordingly. It varies with the type of yarn you use also. Gauge is important for the size of the garment. If your gauge is off, a sweater you intend to knit for a newborn may fit a one year old, for example. There’s nothing worse than getting all done with the sweater and finding out it doesn’t fit.

I’m sorry, I misread how you were to change the needle size. I would just continue with the 7s, but maybe do some decreases. Or you can try 6s, but that may make the lower part very stiff.

Thanks, I think I’ll continue with the 7’s, since that is what I should have ended up with. Do you think I should go additional length to make up for the smaller needle or just go with what I have - I was supposed to do another 28 rows (which is the full lace pattern) in the 7 needles, should I do another full course of the pattern, do you think?

You may not need to do a full pattern repeat, but do some measuring and do enought rows to get to the right finished length.

Thanks I’ll do that - I went to a yarn store today to ask a supposed “expert” and she was no help at all. All she did was criticize the pattern, saying if it was her pattern, she would have decreased it, rather than going down a size in needle. But I told her the pattern keeps 181 stitches throughout and you need all of them to be able to attch the edging, so she really never addressed the needle question and was quite frankly a little _itchy!


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Thank you so much for this response. I was looking around for an answer because I’m an advanced knitter but had never tried to knit with needles much smaller than suggested. I want to make a dog sweater with size 4 worsted weight merino and the suggested needle size is 5.5. The pattern is with a similar yarn and calls for a size 4 for the ribbing around the collar and a 5 for the body but I’m thinking to knit the collar in 3.5 and the body in 4. As I was knitting it felt very thick and dense but now I know it’ll be a more sturdy fabric, especially for a dog that is very active so it’s a non issue as long as I get my gauge right. Thanks for the comment you posted 6 years ago!

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I thought so, too. The larger needles (9) would give the looser floppy-like product, while the smaller needles (7) would be tighter and more dense.

I think you’re getting confused. UK size 7 needles are bigger gauge than size 9 so size 7 would give a looser fabric.