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US Size 13 Knitting Needles (9 mm): Yarn Weight, Gauge and Conversions

Last updated Researched from specs, manuals and owner reviews We earn from qualifying purchases
Quick answer

A US size 13 knitting needle is 9 mm in diameter, old UK and Canadian size 00. It suits super bulky yarn, which knits at 7 to 11 stitches per 4 inches. At about 10 stitches per 4 inches, a 20 inch hat needs about 52 stitches and an 8 inch scarf about 20.

Knitting needle size is the diameter of the shaft, measured in millimeters. This needle is 9 mm, about 0.35 inch across. US size 13 is the American label for a 9 mm needle, and old UK and Canadian size 00 is the same needle. The millimeter figure is the one that matches across every brand, so it is printed on most needles and needle gauges.

What is a US 13 knitting needle in mm and old UK sizes?

US 13 knitting needle conversions
Metric9 mm
Inches (diameter)0.35 in
US size13
Old UK and Canadian size00
Crochet hook, same diameterM/N-13 (9 mm)
Usual yarn weightsuper bulky
Estimated gaugeabout 10 stitches per 4 in

What yarn weight goes with US 13 needles?

The Craft Yarn Council lists 9 mm inside the recommended needle range for the yarn weights below. The hat and scarf columns show how many stitches the full gauge range of each weight gives, so you can see how much the yarn choice moves the numbers.

Yarn weights for 9 mm needles
Yarn weightCYC needle rangeGauge per 4 in20 in hat8 in scarf
Super bulky8 to 12.75 mm (US 11 to 17)7 to 1136 to 5614 to 22

How many stitches do you cast on with US 13 needles?

The estimated gauge places 9 mm within the CYC range for super bulky yarn: the smallest recommended needle gets the most stitches per 4 inches and the largest gets the fewest. That gives about 10 stitches per 4 inches on this needle. Circular pieces are rounded to a multiple of 4 so 2x2 ribbing works out.

Estimated cast-on stitches on 9 mm needles
PieceWidth or circumferenceCast on (estimate)
Hat, 20 in around (multiple of 4)20 inabout 52
Snug hat, 18 in around18 inabout 44
Cowl, 24 in around24 inabout 60
Scarf, 8 in wide8 inabout 20
Baby blanket, 42 in wide42 inabout 105
Throw, 50 in wide50 inabout 125

Swatch before you trust any cast-on number

Knit a swatch at least 6 inches wide, wash and dry it the way you will treat the finished piece, then count stitches across the center 4 inches. Put your real number into the cast-on calculator for an exact count.

Needles and supplies for US 13 (9 mm)

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What crochet hook matches a US 13 knitting needle?

The M/N-13 crochet hook is also 9 mm. Diameter is where the match ends, though: crochet fabric is denser, so CYC pairs super bulky yarn with 8 to 12.75 mm (US 11 to 17) needles but larger hooks. A 9 mm hook usually suits a lighter yarn than a 9 mm needle does.

What are the knitting needle sizes next to US 13?

Needle sizes near 9 mm
NeedleMetricUSOld UKUsual yarnEst. gauge per 4 in
7 mm7 mmNone2Bulky (chunky)about 13
US 118 mm110Super bulkyabout 11
US 139 mm1300Super bulkyabout 10
US 1510 mm15000Super bulkyabout 9.5
US 1712.75 mm17NoneJumboabout 7

Frequently asked questions

What size is a US 13 knitting needle in mm?

A US size 13 needle is 9 mm in diameter, about 0.35 inch. The old UK and Canadian size is 00. US numbers were never fully standardized, so trust the millimeter size printed on the needle or check it in a needle gauge. The neighboring sizes are US 11 (8 mm) and US 15 (10 mm).

What yarn weight do you use with US size 13 needles?

CYC places 9 mm inside the recommended needle range for super bulky yarn. Super bulky is the usual match: its range is 8 to 12.75 mm (US 11 to 17), knitting at 7 to 11 stitches per 4 inches. The size sits inside a single category, so it is a straightforward match. Your pattern gauge matters more than the category name.

How many stitches do I cast on for a hat with US 13 needles?

At about 10 stitches per 4 inches, our estimate for super bulky yarn on 9 mm needles, a 20 inch hat needs about 52 stitches, rounded to a multiple of 4 for ribbing. For a snug fit many patterns size the hat 1 to 2 inches smaller than the head, which is about 44 stitches at 18 inches. The estimate places the needle within the CYC gauge range, so knit a swatch and recount before you cast on.

How many stitches for a scarf on US 13 needles?

Cast on about 20 stitches for an 8 inch wide scarf at 10 stitches per 4 inches. A 6 inch scarf needs about 15 and a 10 inch scarf about 25. Stitch pattern changes both width and yarn: garter stitch used about 46 percent more yarn than stockinette in one test. A quick 4 inch swatch in the stitch you plan to use gives a better count than the label gauge.

What crochet hook is the same size as a US 13 knitting needle?

The M/N-13 crochet hook is also 9 mm, so the two share a diameter. They are not interchangeable for the same yarn, though. CYC pairs super bulky yarn with 8 to 12.75 mm (US 11 to 17) needles but 9 to 15 mm (M-13 to Q) hooks, because crochet fabric is denser. A 9 mm hook usually suits a lighter yarn than a 9 mm needle does.

Are US size 13 needles good for beginners?

They can be, for quick projects. At 9 mm a throw can be as few as 125 stitches across, so finished pieces appear fast and stitches are easy to see. The trade-offs are heavy yarn, large loops that loosen easily and less forgiving tension, so start with a cowl or scarf before a blanket.

How we research: we compare manufacturer specifications, owner manuals, published standards and recurring themes in verified owner reviews. We do not test products in person, and this is researched guidance, not professional advice. Follow your machine manual and pattern, and take care with rotary cutters, hot irons and needles. As an Amazon Associate we earn from qualifying purchases.