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Knitting Needle Size Chart & Converter

Convert Metric, US, legacy UK/Canadian, and Japanese (Clover / bamboo profile) sizes. Every result says whether it is published, nearest, or source-dependent.

I have a size in

Metric US Old UK / CA Japanese*

The selected system interprets a bare number. You can also type “4.5 mm”, “US 8”, “old UK 8”, or “Japanese 8”.

Needle size

Results update as you type. Fractions such as 10½ and decimal commas are accepted.

Try:

Published nominal match

Interpreting “8” as US 8

Physical shaft diameter

5 mm

0.1969 in

Metric: 5 mmPhysical diameter
US: 8Published by CYC
Old UK / CA: 6Historical nominal
Japanese*: 10号Nearest +0.1 mm

Needle numbers are nominal and may vary by maker. Millimetres are the safest comparison point.

Common starting range: Medium / worsted and aran. Always follow the pattern gauge and swatch.

Knitting Needle Size Chart · Data reviewed 2026-08-19 · https://knittingneedlesizechart.com/

Relative diameter view

See the step, not just the number.

5 mm sits between a 4.5 mm and 5.25 mm listed size.

Enlarged relative view. Screen scaling varies; do not use this as a physical needle gauge.

The complete reference

Full knitting needle size chart

Sorted by shaft diameter. A repeated number means published sources or manufacturers use more than one diameter.

On a narrow screen, scroll the chart sideways; the Metric column stays pinned.

Knitting needle shaft diameters with published US, legacy UK/Canadian, and Japanese (Clover / bamboo profile) labels. A dash means no published match in this data profile.
Metric diameter	US nominal	Old UK / Canadian	Japanese*	Note
1.5 mm	000, Published nominal label	No published match	No published match
1.75 mm	00, Published nominal label	No published match	No published match
2 mm	0, Published nominal label	14, Historical nominal label	No published match
2.1 mm	No published match	No published match	0号, Manufacturer profile	Japanese profile
2.25 mm	1, Published nominal label	13, Historical nominal label	No published match
2.4 mm	No published match	No published match	1号, Manufacturer profile	Japanese profile
2.5 mm	1½, Manufacturer profile	No published match	No published match
2.7 mm	No published match	No published match	2号, Manufacturer profile	Japanese profile
2.75 mm	2, Published nominal label	12, Historical nominal label	No published match
3 mm	2½, Manufacturer profile2/3, Multiple or conflicting published matches	11, Historical nominal label	3号, Manufacturer profile	Published values vary
3.125 mm	3, Multiple or conflicting published matches	No published match	No published match	Published values vary
3.25 mm	3, Multiple or conflicting published matches	10, Multiple or conflicting published matches	No published match	Published values vary
3.3 mm	No published match	No published match	4号, Manufacturer profile	Japanese profile
3.5 mm	4, Published nominal label	10, Multiple or conflicting published matches9, Multiple or conflicting published matches	No published match	Published values vary
3.6 mm	No published match	No published match	5号, Manufacturer profile	Japanese profile
3.75 mm	5, Published nominal label	9, Multiple or conflicting published matches	No published match	Published values vary
3.9 mm	No published match	No published match	6号, Manufacturer profile	Japanese profile
4 mm	6, Multiple or conflicting published matches	8, Historical nominal label	No published match	Published values vary
4.2 mm	No published match	No published match	7号, Manufacturer profile	Japanese profile
4.25 mm	6, Multiple or conflicting published matches	No published match	No published match	Published values vary
4.5 mm	7, Published nominal label	7, Historical nominal label	8号, Manufacturer profile
4.8 mm	No published match	No published match	9号, Manufacturer profile	Japanese profile
5 mm	8, Published nominal label	6, Historical nominal label	No published match
5.1 mm	No published match	No published match	10号, Manufacturer profile	Japanese profile
5.25 mm	9, Multiple or conflicting published matches	No published match	No published match	Published values vary
5.4 mm	No published match	No published match	11号, Manufacturer profile	Japanese profile
5.5 mm	9, Multiple or conflicting published matches	5, Historical nominal label	No published match	Published values vary
5.7 mm	No published match	No published match	12号, Manufacturer profile	Japanese profile
5.75 mm	10, Multiple or conflicting published matches	No published match	No published match	Published values vary
6 mm	10, Multiple or conflicting published matches	4, Historical nominal label	13号, Manufacturer profile	Published values vary
6.3 mm	No published match	No published match	14号, Manufacturer profile	Japanese profile
6.5 mm	10½, Published nominal label	3, Historical nominal label	No published match
6.6 mm	No published match	No published match	15号, Manufacturer profile	Japanese profile
7 mm	10¾, Manufacturer profile11, Multiple or conflicting published matches	2, Historical nominal label	No published match	Published values vary
7.5 mm	10⅞, Manufacturer profile11, Multiple or conflicting published matches	1, Historical nominal label	No published match	Published values vary
8 mm	11, Multiple or conflicting published matches	0, Historical nominal label	No published match	Published values vary
9 mm	13, Published nominal label	00, Historical nominal label	No published match
10 mm	15, Published nominal label	000, Historical nominal label	No published match
12 mm	17, Multiple or conflicting published matches	No published match	No published match	Published values vary
12.5 mm	17, Multiple or conflicting published matches	No published match	No published match	Published values vary
12.75 mm	17, Multiple or conflicting published matches	No published match	No published match	Published values vary
15 mm	19, Published nominal label	No published match	No published match
19 mm	35, Multiple or conflicting published matches	No published match	No published match	Published values vary
20 mm	35, Multiple or conflicting published matches	No published match	No published match	Published values vary
25 mm	50, Published nominal label	No published match	No published match
30 mm	No published match	No published match	No published match	Metric-labelled size
35 mm	70, Published nominal label	No published match	No published match

Manufacturer profile, not a universal number.

Multiple or conflicting published matches exist.

Japanese profile: Japanese (Clover / bamboo profile). Product lines can differ. Tulip metal needles label sizes 0–2 as 2.00, 2.50, and 2.75 mm, while its bamboo profile and Clover use 2.10, 2.40, and 2.70 mm.

Data reviewed 2026-08-19. Method and live source links: https://knittingneedlesizechart.com/#sources

Stored only on this device

My needle roll

No saved sizes yet. Save a result to make a quick local reference.

The next decision

Compare two diameters

A half-millimetre can look small as a number. Compare it as a physical diameter before you swatch.

Selected size 5 mm

Compare with 6.5 mm

6.5 mm is 1.5 mm larger—a 30% diameter difference.

Relative cross-sections—not a measuring gauge.

Gauge rescue

Too many stitches or too few?

This gives a direction and the next general-use comparison step only. It never predicts a guaranteed needle size.

Try a larger needle 5.25 mm is the next general-use step in this guide. Swatch again with the same yarn, stitch pattern, washing, and blocking. The result is not guaranteed.

Pattern rescue

“Size 8” is not one needle.

The same bare number can mean 5 mm in the US, about 4 mm in a legacy UK/Canadian pattern, or 4.5 mm in the selected Japanese profile.

Starting guidance, not a recipe

Needle size by yarn weight

These Craft Yarn Council ranges are common starting points. Lace may deliberately use larger needles for openwork, and your pattern gauge takes priority.

Craft Yarn Council yarn weights, stockinette gauge per 4 inches, and starting knitting needle diameter ranges.
Yarn category	Stitches / 4 in	Starting needle range
0 LaceLace / thread	33–40	1.5 mm–2.25 mm
1 Super FineFingering / sock	27–32	2.25 mm–3.25 mm
2 FineSport / baby	23–26	3.25 mm–3.75 mm
3 LightDK / light worsted	21–24	3.75 mm–4.5 mm
4 MediumWorsted / aran	16–20	4.5 mm–5.5 mm
5 BulkyChunky / bulky	12–15	5.5 mm–8 mm
6 Super BulkySuper bulky	7–11	8 mm–12.75 mm
7 JumboJumbo / roving	6 or fewer	12.75 mm and larger

Source: Craft Yarn Council's YarnStandards.com. Guidelines only.

When the marking wore off

Measure an unmarked needle

01
Use a real needle gauge
Slide the shaft—not the tapered tip—through progressively smaller holes.
02
Stop at the smallest easy fit
Do not force the needle. Read the millimetre label beside that hole.
03
Return here by millimetres
Use the physical diameter as the anchor, then check your pattern gauge and swatch.

A screen drawing is not a physical gauge. Use a real needle gauge and read its millimetre marking.

Method and provenance

Why some rows have more than one answer

Needle-number systems are labels, not formulas. This chart stores shaft diameter as the key and attaches every non-metric label to a named source profile.

Match language

Physical diameter: The shaft measurement in millimetres.
Published nominal: A source associates this number with this diameter; makers may still vary.
Multiple published matches: The same number appears at more than one diameter. Every candidate stays visible.
Nearest: No label exists at the selected diameter. The result shows the signed millimetre difference and is not an equivalent.

Reviewed sources

Dataset reviewed 2026-08-19. Japanese number labels are shown as manufacturer profiles, not as a universal physical standard.