Size 4 knitting needles in mm

Convert US size 4 knitting needles to millimeters and old UK sizes. See nearby needle sizes and yarn weight suggestions.

KnittingNeedle sizesConversion

This page is tuned for the exact search query and shows how this size looks in metric (mm), US sizes, and old UK sizes. It also lists nearby needle sizes so you can adjust your gauge if needed.

Adjust needle size

You landed here from a size-specific search, but you can still switch systems and values to explore other conversions.

Sizing system

Needle size

Change this value to see other sizes. We will always snap to the closest standard needle in the chart.

Size 4 knitting needles (3.5 mm, UK -)

3.5mm

4US size

-UK old size

Typical yarn weight for this size: DK.

Needle size is always about diameter in mm. US and UK numbers are just labels. If the mm value matches, the needles are the same size, even when the printed numbers look different.

When substituting needles for a pattern, match the mm size first. Then knit a small swatch and adjust up or down one size if your gauge is too tight or too loose.

Nearby needle sizes

If this size feels too tight or too loose, these are the next sizes knitters usually move to.

Metric (mm)	US size	UK old size	Yarn weight
2.8 mm	US 2	UK 12	sport
3 mm	US 2.5	UK 11	sport / DK
3.3 mm	US 3	UK 10	DK
3.5 mm	US 4	UK -	DK
3.8 mm	US 5	UK 9	DK / light worsted
4 mm	US 6	UK 8	worsted
4.5 mm	US 7	UK 7	worsted

See the full knitting needle conversion chart

This page focuses on one size, but the full chart lists every standard needle size in mm, US, and old UK systems. You can download it or print it as a reference.

Open full chart →