Familiar concepts like gauge, yarn weight, and wraps per inch have been on my mind lately. I am going through the massive number of details that crop up as we bring patterns closer to final release.
Yarn by Weight
This concept is understood by everyone. Is it? I admit I get confused: are sock and fingering the same? Why aren’t all worsted yarns the same? Why do needles that work with one yarn of a weight, but not give the same results in another yarn of the same? And, I have no idea what the number correlations are that the Craft Yarn Council uses.
I use a table I found somewhere and have adapted it to my needs when these questions crop up, but there doesn’t appear to be any “standards” that are available at my level of access. Like sizing, this is something that seems to be flexible and changes between sources, so is incredibly difficult to fully understand.
Jill’s Yarn Weight Table
Yarn Weights | Yarn WPI | Yards per ounce | Yards per 1g | per 100g | Yards per 1g | per 50g | ||||
low WPI | High WPI | Yards low | Yards high | low | 3.5 | ounces | high | 1.75 | ounces | |
Lace | 25 | and above | 187.5 | 375 | 6.5 | 656 | 1313 | 13.125 | 328 | 656 |
Baby | 150 | 187.5 | 5.25 | 525 | 656 | 6.5 | 263 | 328 | ||
Fingering | 20 | 25 | 112.5 | 150 | 4 | 394 | 525 | 5.25 | 197 | 263 |
Sport | 17 | 20 | 81.25 | 112.5 | 2.875 | 284 | 394 | 4 | 142 | 197 |
DK | 13 | 16 | 62.5 | 87.5 | 2.25 | 219 | 306 | 3 | 109 | 153 |
Worsted | 9 | 12 | 56.25 | 68.75 | 2 | 197 | 241 | 2.375 | 98 | 120 |
Aran | 6 | 10 | 43.75 | 62.5 | 1.5 | 153 | 219 | 2.25 | 77 | 109 |
Bulky | 6 | 8 | 25 | 43.75 | 0.875 | 88 | 153 | 1.5 | 44 | 77 |
Chunky | up to | 4 | 25 | 0 | 0 | 88 | 0.875 | 0 | 44 |
Testing the Concepts
I have made three Chattanooga Cosies (one not knit by me). All are in fingering weight yarn, but none fit nicely within the table above. Trouble is, even though they are all fingering, I get different stitch and row/ round gauges, and my WPI (wraps per inch) and TPI (twists per inch) are different from both the table and Ravelry.
Chattanooga Cosy Fingering Yarn
n | Needle | sts per inch / cm | rounds per inch / cm | yards per 100g | meters per 100g | fiber content | WPI | Jill's WPI |
Silk Sock | 6 US[4mm] | 4.25 | 4.5 | 400 | 366 | 80% merino/20% silk | 14 | 16 |
Solemate | 6 US[4mm] | 4.25 | 6 | 376 | 344 | 55% merino/30% viscose/15% nylon | 14 | 18 |
Notting Hill | 6 US[4mm] | 4.5 | 7 | 470 | 430 | 85% super wash merino/15% biodegradable nylon | na | 17 |
Trying to Break It Down
The first thing I always at is yard/meters and skein weight. These three skeins are all listed as weight 100g. Yay, something is the same! There is about a 100 yard / meter difference from lightest to heaviest in this. All are 3-ply.
Take a look at the fibers. They are all contain super wash merino, but otherwise have different fiber makeups. Without access to industry weight comparisons, it is difficult to know the relative weights of the fibers used. This could be a key element to concepts like yarn substitution, but it is not readily available.
- Silk sock has 80% merino, 20% silk and no nylon, and
- Solemate, with the fewest yards, has 55% merino, 30% viscose, plus 15% nylon,
- Notting Hill has 85% merino, 15% biodegradable nylon.
Visually, I would say that Silk Sock (WPI 16) and Solemate (WPI 18) appear to be the same size, with Notting Hill (WPI 17) appearing to be almost light fingering. But the WPI doesn’t necessarily agree. I do not get WPI 14 (what comes up on Ravelry) when I wrap them. I think viscose is heavier than wool, but I cannot verify it. Nylon seems to depend on the chemical makeup. All fiber weight depends on density of fiber.
Looking for Concepts That Explain Differences
I counted TPI too. The yarn with most yardage has the highest twist, but that is the only correlation I can find.
Back to Gauge
Going deeper on gauge, my base gauge is 4.25 sts per inch/2.54 cm and 4.5 rows/rounds per inch/2.54 cm using Silk Sock. The stitch gauge is matched in Solemate, and is 4.5 for Notting Hill. This would match my experience with the finished pieces.
Row gauge varies quite a bit. Solemate is 6 rounds per inch and Notting Hill is 7 rounds. I’ve used the Rounds Calculator to calculate the number of rounds I needed to get the same length at the sample sizes. Below are the graphics. I needed 38 additional rows at the back for Solemate, and 61 for Notting Hill. It actually worked out for both to have less length since I am pretty short waisted, but we added 19 rounds to the Solemate sample. So feel free to use the Rounds Calculator!


What To Do
If 38 rows or 61 rows need to be added, and there are 7 places to add rounds, how are you going to do that? To add 38 rounds evenly, it would be to work an additional 5.43 rounds 7 times. For this to be done evenly, you need high and low numbers. As an easy solution, add 4 rounds twice, 5 rounds twice, 6 rounds twice, and 8 rounds on the last section. Knitters Math can teach you how to calculate that!
To add 61 rounds evenly would result in 8.71 rounds 7 times. Again, high and low numbers are needed. An easy solution would be to add 6 rounds twice, 8 rounds twice, 10 rounds twice, and 13 rounds on the last section.
There are more complicated ways to solve this puzzle, but since Chattanooga doesn’t require a precise fit, I would not bother making them. In a garment this can become crucial.
The Bigger Concepts
A place where this row gauge difference might be significant is in a piece with shaping. If the shaping was meant to be done over 2″/5.1 cm at 4.5 rows/rounds (over 9 rounds), but I was working at 6 or 7 rows/rounds, I would need to work the shaping over a different number of rows/rounds, and the spacing of my increases or decreases needs to change. This will make a huge difference when making a garment. Failure to respect the difference in row gauge will end up with scrunched shaping which will not suit the purpose of the original shaping.
Respacing is a bit more difficult than just adding additional rounds. At the two other row/round gauges I need to work the shaping over 12 and 14 rows/rounds. Let’s say I’m doing 5 shaping rounds at the original gauge (every other row/round). I still need to do 5 shaping rounds, but I need to do them every 2.4 rows/rounds or 2.8 rows/rounds (12/5 or 14/5). Some of the shaping will be done every 3 rows/rounds and some every 2 rounds.


Once again, you would need to figure out high and low spacing. Knitters Math can teach you how to calculate that!
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