Yarn weights, nought to seven, and what each one is good for
The drawer on the porch has every weight in it from lace to jumbo, and the circle argues about two of them every Tuesday. This is the chart I keep taped inside the lid: what each weight is for, which hook it wants, and how the US numbers line up with the UK words.
| Number | Weight name | US name | UK name | Hook | Sts per 4 in | What it gets used for here |
|---|---|---|---|---|---|---|
| 0 | Lace | Fingering / Crochet Thread | Cobweb / 2-ply | 1.5–2.25mm | 32–42 sc | Doilies and thread work, in daylight |
| 1 | Super Fine | Sock / Fingering | 4-ply | 2.25–3.5mm | 21–32 sc | Socks and shawls that fold up small |
| 2 | Fine | Sport / Baby | Sport | 3.5–4.5mm | 16–20 sc | Baby blankets, a light cardigan |
| 3 | Light | DK / Light Worsted | DK | 4–5.5mm | 12–17 sc | Finer squares, small toys, wearables |
| 4 | Medium | Worsted / Aran | Aran | 5.5–6.5mm | 11–14 sc | Nearly everything on this porch |
| 5 | Bulky | Chunky / Craft / Rug | Chunky | 6.5–9mm | 8–11 sc | A blanket inside a fortnight; baskets |
| 6 | Super Bulky | Super Bulky / Roving | Super Chunky | 9–15mm | 7–9 sc | Throws for the arm of the glider |
| 7 | Jumbo | Jumbo / Roving | — | 15mm+ | 6 sc or fewer | Rugs and arm work. Nothing subtle |
Eight numbers, nought through seven. Nought is lace and seven is jumbo, and sitting in the middle is four — worsted, or medium, which is what a granny square wants and what nearly every pattern on this porch will ask for. Four takes a 5–5.5mm hook (H or I). Three, which is DK, takes 4mm (G). Lace wants a steel hook at 1.5–2.25mm and good afternoon light. The number is printed on the ball band inside a little skein shape, so you are not guessing. And when two balls disagree with each other, believe the gauge rather than the number — gauge is stitches across four inches, and it is the one thing on that band somebody actually measured.
Reading a ball band without your glasses on
Two things on the band are worth putting your glasses on for, and one thing that is not printed there at all matters more than either.
The number in the little skein
Turn the ball until you find the little skein outline. The number inside it, nought to seven, is the whole answer — that is the Craft Yarn Council category and it is the same shape on every brand that bothers. Underneath it there are usually two more things: a hook size and a gauge, written as stitches across four inches, or across ten centimetres, which is the same span in a different language.
The yardage, which is on the back if it is anywhere
What is not on the band, and matters more than the grams, is the yardage. Patterns are written in yards or metres because that is what runs out. A hundred grams of worsted is somewhere around two hundred yards, call it a hundred and eighty metres; the same weight of DK gives you closer to half again as much, because thinner yarn goes further. If you are buying to a pattern, count yards. If you are buying because you liked the colour, count nothing and enjoy yourself.
One step either way, and no further
You can move one number up or one number down from what a pattern asks for, as long as you move the hook to match and check your gauge before you commit to forty squares. Going down from worsted to DK with a slightly smaller hook gives you a tighter, tidier surface, which is exactly what you want on a small toy. Going up from worsted to bulky halves the evenings a blanket takes, and you will feel that in your wrist as well.
Two steps is where it stops being a substitution and starts being a different project. The gauge difference compounds every round, so a square that was meant to be six inches finishes at four or at nine and nothing joins to anything. If you want the yarn badly enough, work one square, measure it, and rewrite the round counts around what you actually got. That is a fair afternoon's work and it is honest — it is just not a substitution.
The same number, in three different fibres
Every weight comes in cotton, in acrylic, in wool, and in blends of those, and they behave differently while measuring the same. Cotton shows each stitch cleanly and holds whatever shape you worked into it, so it is what the circle reaches for when the stitches themselves are the point. Acrylic is soft, cheap enough to make mistakes in, and washes without ceremony — there is no shame in it and most first blankets are made of it. Wool blocks like a dream and then wants hand-washing forever after. Cotton-acrylic blends land in the middle and are the sensible answer for anything going to a baby.
Asked on the porch
Which weight should I buy if I only buy one?
Worsted, number four. It is the weight most patterns assume, it pairs with a 5mm or 5.5mm hook, and it gives you 11–14 single crochets across four inches. Stitches that size are big enough to see what you did wrong, which matters more than anything else at the start.
What weight is right for a small stuffed toy?
Worsted cotton, worked tighter than the band suggests, is the usual answer — it keeps its edges and the stuffing stays where you put it. DK, number three, gives a finer toy at the cost of more rounds. Both are correct; pick the finished size you want and work back from there.
Which hook out of the jar suits worsted?
5mm or 5.5mm — US H or I. For anything that will be stuffed, drop to 4mm or 4.5mm so the fabric closes up and nothing shows through the gaps.
My ball says light worsted. Is that DK?
Near enough to swap, not near enough to ignore. Both sit at number three, and light worsted is a touch heavier of the two. Move the hook half a millimetre and check a square before you trust it.
Worsted or aran — are those two names for one yarn?
In US terms, yes, both are number four and you can treat them as one. In UK terms aran means specifically the heavier end of that band, which an American pattern would call a heavy worsted. It is one shelf, described from two sides of an ocean.
Can I use a yarn from a different weight than the pattern says?
One number in either direction, with the hook adjusted and a square measured first. Beyond that the finished size and the drape both drift too far, and you are better off rewriting the counts than hoping.