Yarn Weight Calculator – Grams, Yards, Meters & WPI

Three conversions in one card: grams to yards using your label’s own ratio (the exact method), meters and yards either way, and wraps per inch to name a mystery yarn’s weight class.

The label’s two numbers set the ratio, and the ratio converts any weight of that yarn: a full stash or a half-used skein.

Label: grams per skein

Label: yards per skein

Your yarn weighs grams, on a kitchen scale

You have

138.6yards

63 g at 2.20 yd per gram

In meters126.7 m
Yards per gram2.200
A full skein220 yd (201 m)

The Formulas

yards = grams × (label yards ÷ label grams) · meters = yards × 0.9144

The label ratio is exact for that yarn: better than any per-weight table, because a dense cotton worsted and an airy wool worsted differ by half their yardage at the same 100 g.

Worked Example

A part-used skein weighs 63 g; the label reads 100 g / 220 yd:

Ratio: 220 ÷ 100 = 2.2 yards per gram.
63 × 2.2 = 138.6 yd (127 m) still in the skein: enough for a hat, shy of a second mitten.

Weight Classes, WPI, and Typical Yardage

Craft Yarn Council classes with their WPI counts; the per-100 g column is typical and swings with fiber, the label ratio above outranks it.

Class	Also called	WPI	Typical yd per 100 g
0 · Lace	thread, light fingering	30+	500+
1 · Super fine	fingering, sock	14–30	380–460
2 · Fine	sport	12–18	300–380
3 · Light	DK	11–15	230–300
4 · Medium	worsted, aran	9–12	190–230
5 · Bulky	chunky	6–9	100–190
6 · Super bulky	roving	5–6	60–100
7 · Jumbo	arm-knitting	under 5	under 60

How to Measure Your Inputs

Grams: a kitchen scale in gram mode; subtract nothing for the ball band if you removed it, a gram if it’s still on.
WPI: wrap around anything with a flat inch: a ruler, a WPI tool, a pencil marked at an inch. Even tension, wraps touching, no squeezing.
No label? Measure WPI for the class, then borrow the ratio from a labeled yarn of the same class and fiber for a usable estimate.

Assumptions and Defaults

1 yard = 0.9144 m exactly; results round to one decimal.
WPI ranges follow the Craft Yarn Council; yarns at a boundary belong to either class, and your gauge swatch settles it.
The typical-yardage column assumes plied wool-style yarns; cotton runs denser (fewer yards), brushed mohair lighter.

Conversion Questions, Answered

How do I convert grams of yarn to yards?

To convert grams of yarn to yards, multiply the grams by the label’s yards per gram, so a 63 g remnant from a 100 g / 220 yd skein holds 63 × 2.2 = 138.6 yd. Without a label, find the yarn’s WPI class and use the ratio from a label in the same class.

How much yarn is left in my skein?

To find how much yarn is left in a skein, weigh it and run the grams-to-yards conversion above. Weighing before you start a sleeve or a second sock tells you whether you will run short while there is still time to buy more.

What are wraps per inch?

Wraps per inch measure a yarn’s thickness: wrap the strand snugly around a ruler and count the wraps in one inch, so ten wraps suggests worsted and sixteen suggests sport. The published ranges overlap, with eleven fitting both DK and worsted, so the calculator names every class a count fits and a swatch decides between them.

How many meters in a yard?

A yard is exactly 0.9144 meters, so a 200 m ball of yarn holds 218.7 yd. European labels give meters and US patterns give yards, and the meters tab converts in either direction, which helps when a pattern and its yarn come from different countries.

Weight classes and WPI: Craft Yarn Council standards.