Yarn Weight & Wpi
One way of determining the weight of an unknown yarn is to use the wrapping method. This convenient method is also used to calculate the amount of yarn needed for a project. By this method it is possible to check yarn with a simple pencil and ruler Wrap the yarn around a large needle or a ruler. Make sure the yarn lies flat. Push the yarn together so there are no gaps between wraps. Smooth it out so it is neither too loose nor too tight. Measure the number of wraps per inch (2.5 cm).
The number of wraps will act as a gauge to assess the thickness of unmarked yarn; for example 12 wraps per inch is 12 WPI, and is used to calculate how much yarn is required for various articles so that 12 WPI is equivalent to 8 ply (worsted weight, medium weight) yarn.
|
US |
UK |
Australia |
m/100g |
Wraps Per Inch, |
Recommended knitting needle size, mm |
Recommended crochet hook size, mm |
Other terms used |
|
0 or Lace |
1 ply |
More than 800 |
40+ wpi |
1.5 - 2.5 |
1.5 - 2.5 |
Single, Cobweb, Thread, Zephyr |
|
|
0 or Lace |
2 ply |
600-800 |
30-40 wpi |
1.5 - 2.5 |
1.5 - 2.5 |
||
|
1 or Super Fine |
3 ply |
3 ply |
500-600 |
20-30 wpi |
2 - 3 |
2.25 - 3.5 |
Light Fingering, Sock, Baby |
|
1 or Super Fine |
4 ply |
4 ply |
350-450 |
14-24 wpi |
2 - 3 |
2.25 - 3.5 |
Fingering, Sock, Baby |
|
2 or Fine |
5 ply |
250-350 |
12-18 wpi |
3 - 4 |
3.5 - 4.5 |
Sport, Baby, 3-ply (obsolete American) |
|
|
3 or Light |
DK (Double Knit) or 8 ply |
8 ply |
200-250 |
11-15 wpi |
4 - 4.5 |
4.5 - 5.5 |
Light Worsted, DK |
|
4 or Medium |
Worsted, Aran, Triple Knit (rare) |
10 or 12 ply |
120-200 |
9-12 wpi |
4.5 - 5.5 |
5.5 - 6.5 |
Worsted, Afghan, Fisherman, 4-ply (obsolete American) |
|
5 or Bulky |
Chunky, Double Double Knit (rare) |
12 or 16 ply |
100-130 |
6-8 wpi |
5.5 - 8 |
6.5 - 9 |
Craft, Rug |
|
6 or Super Bulky |
Super Chunky |
Less than 100 |
5-6 wpi |
>8 |
>9 |
Roving |
|
|
7 or Jumbo |
Less than 100 |
n/a |
12.75 mm and larger |
15 mm and larger |
|