US Size 17 Knitting Needles (12.75 mm): Yarn Weight, Gauge and Conversions
A US size 17 knitting needle is 12.75 mm in diameter. It suits super bulky and jumbo yarn, and jumbo knits at 6 or fewer stitches per 4 inches. At about 7 stitches per 4 inches, a 20 inch hat needs about 36 stitches and an 8 inch scarf about 14.
Knitting needle size is the diameter of the shaft, measured in millimeters. This needle is 12.75 mm, about 0.50 inch across. US size 17 is the American label for a 12.75 mm 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 17 knitting needle in mm and old UK sizes?
| Metric | 12.75 mm |
|---|---|
| Inches (diameter) | 0.50 in |
| US size | 17 |
| Old UK and Canadian size | None |
| Crochet hook, same diameter | None on the CYC chart |
| Usual yarn weight | jumbo |
| Estimated gauge | about 7 stitches per 4 in |
Some charts also list the sizes below. They are close enough to 12.75 mm that they share this page.
| Metric | US | Old UK | Note |
|---|---|---|---|
| 12.5 mm | 17 | None | CYC lists both 12.5 and 12.75 mm as US 17. |
What yarn weight goes with US 17 needles?
The Craft Yarn Council lists 12.75 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 weight | CYC needle range | Gauge per 4 in | 20 in hat | 8 in scarf |
|---|---|---|---|---|
| Super bulky | 8 to 12.75 mm (US 11 to 17) | 7 to 11 | 36 to 56 | 14 to 22 |
| Jumbo | 12.75 mm (US 17) and larger | 6 or fewer | up to 32 | up to 12 |
How many stitches do you cast on with US 17 needles?
The estimated gauge places 12.75 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 7 stitches per 4 inches on this needle. Circular pieces are rounded to a multiple of 4 so 2x2 ribbing works out.
| Piece | Width or circumference | Cast on (estimate) |
|---|---|---|
| Hat, 20 in around (multiple of 4) | 20 in | about 36 |
| Snug hat, 18 in around | 18 in | about 32 |
| Cowl, 24 in around | 24 in | about 44 |
| Scarf, 8 in wide | 8 in | about 14 |
| Baby blanket, 42 in wide | 42 in | about 74 |
| Throw, 50 in wide | 50 in | about 88 |
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 17 (12.75 mm)
Bernat Blanket Super Bulky Chenille Yarn, 3 pack
$21.81Three 150 g, 108 yard balls of 100 percent polyester super bulky yarn made for blankets.
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Authentic Knitting Board 38 inch Adjustable Blanket Loom
$69.99A 38 inch solid hardwood loom with 170 pegs, 84 of them double, for wide panels such as blankets.
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KnitIQ Blocking Mats, 9 piece set with T-pins
$54.99Nine 0.75 inch thick mats with 100 T-pins and a storage bag for blocking finished pieces.
Check pricePrices change often, so confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.
What crochet hook matches a US 17 knitting needle?
No standard crochet hook is exactly 12.75 mm on the CYC chart. The nearest are 12 mm and P/Q (15 mm). For the same yarn, crochet usually calls for a bigger tool than knitting.
What are the knitting needle sizes next to US 17?
Frequently asked questions
What size is a US 17 knitting needle in mm?
A US size 17 needle is 12.75 mm in diameter, about 0.50 inch. There is no old UK number for it on common conversion charts. Charts also list 12.5 mm (US 17), covered on this page. 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 15 (10 mm) and US 19 (15 mm).
What yarn weight do you use with US size 17 needles?
CYC places 12.75 mm inside the recommended needle range for super bulky and jumbo yarn. Jumbo is the usual match: its range is 12.75 mm (US 17) and larger, knitting at 6 or fewer stitches per 4 inches. Because 12.75 mm sits where two categories meet, it makes the lighter yarn slightly loose and the heavier yarn slightly firm. Your pattern gauge matters more than the category name.
How many stitches do I cast on for a hat with US 17 needles?
At about 7 stitches per 4 inches, our estimate for super bulky yarn on 12.75 mm needles, a 20 inch hat needs about 36 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 32 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 17 needles?
Cast on about 14 stitches for an 8 inch wide scarf at 7 stitches per 4 inches. A 6 inch scarf needs about 11 and a 10 inch scarf about 18. 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 17 knitting needle?
No standard crochet hook is exactly 12.75 mm on the CYC chart. The nearest are 12 mm and P/Q (15 mm). They are not interchangeable for the same yarn, though. CYC pairs jumbo yarn with 12.75 mm (US 17) and larger needles but 15 mm (Q) and larger hooks, because crochet fabric is denser. A 12.75 mm hook usually suits a lighter yarn than a 12.75 mm needle does.
Are US size 17 needles good for beginners?
They can be, for quick projects. At 12.75 mm a throw can be as few as 88 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.