Conversion Guide

UK to US Knitting Needle Size Conversion

Working from a British, Australian, or vintage pattern? UK needle sizes run the opposite direction to US sizes. Here's the complete conversion chart.

Key conversions at a glance

UK 14 = US 0  ·  UK 8 = US 6  ·  UK 6 = US 8  ·  UK 4 = US 10  ·  UK 000 = US 15

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UK to US Conversion Chart

All UK needle sizes sorted from smallest to largest, with US equivalents and metric (mm) measurements. UK sizes run from 14 (finest) to 000 (largest).

UK Size US Size Metric (mm) Yarn Weight
UK 14 US 0 2 mm Fingering / Sock
UK 13 US 1 2.25 mm Fingering / Sock
UK 12 US 2 2.75 mm Sport / DK
UK 11 US 2.5 3 mm Sport / DK
UK 10 US 3 3.25 mm Sport / DK
UK 9 US 5 3.75 mm DK / Worsted
UK 8 US 6 4 mm DK / Worsted
UK 7 US 7 4.5 mm Worsted / Aran
UK 6 US 8 5 mm Worsted / Aran
UK 5 US 9 5.5 mm Bulky / Chunky
UK 4 US 10 6 mm Bulky / Chunky
UK 3 US 10.5 6.5 mm Bulky / Chunky
UK 2 7 mm Bulky / Chunky
UK 1 7.5 mm Bulky / Chunky
UK 0 US 11 8 mm Super Bulky / Jumbo
UK 00 US 13 9 mm Super Bulky / Jumbo
UK 000 US 15 10 mm Super Bulky / Jumbo

Understanding the UK Needle System

UK knitting needle sizes were based on the British Standard Wire Gauge — an industrial system for measuring wire thickness where higher gauge numbers indicate thinner wire. When knitting needles were standardized in Britain, they inherited this logic: higher UK numbers mean thinner needles.

The UK scale runs from size 14 (the thinnest standard needle at 2.0 mm) to size 000 (the thickest at 10.0 mm). For needles larger than 10 mm, there is no UK number — modern British and Australian patterns use metric (mm) sizing for bulky needles.

Working from vintage British patterns

Vintage British knitting patterns from the 1950s–1980s are widely shared on Ravelry and knitting communities. These patterns almost always list only the UK needle size with no mm equivalent. Use the chart above to find the correct needle, and always knit a gauge swatch — old patterns were written for specific yarn weights that may differ from modern equivalents.

Australian and Canadian sizing

Australian and Canadian patterns historically used the same system as UK sizing. A pattern from Australia calling for "No. 8 needles" means UK/Australian size 8, which is 4.0 mm (US 6). Modern Australian patterns use metric sizing.

Frequently Asked Questions

What US size is UK 8? +
UK size 8 is 4.0 mm, which equals US size 6. Do not confuse UK 8 with US 8 — they are completely different needle sizes (US 8 is 5.0 mm).
What US size is UK 10? +
UK size 10 is 3.25 mm, which equals US size 3.
What does UK size 000 equal in US? +
UK size 000 is 10.0 mm, which equals US size 15. This is the largest size in the traditional UK scale.
My vintage pattern says "No. 9 needles" — what does that mean? +
UK/old British size 9 is 3.75 mm, which equals US size 5. Always double-check the gauge information in the pattern to confirm.
Why doesn't the UK system cover very large needles? +
The UK wire gauge system only extended to sizes used in traditional knitting. Bulky and super-bulky yarn are a relatively modern development — when larger needles became needed, the industry simply adopted metric sizing rather than extending the old scale.