convertimate Crochet hook sizes

Millimeters to US numbers

Type a value in mm to get it in US instantly.

10US

That's 1.09× as thick as the hook for worsted yarn, while the hook for bulky yarn is 1.33× thicker.

What it means

Which yarn suits that hook?

Steel hooks for thread use a separate, reversed numbering and are not covered here. Brands differ slightly above 6 mm.

The math

How to convert mm to US

Hook sizes are a table: H-8 = 5 mm, G-6 = 4 mm, J-10 = 6 mm. The letter and the number name the same hook.

Example: 6 mm = 10 US.

Every unit

That hook in every system

Tables

mm to US conversion table

mm to US conversion table
mmUS
2.25 mm1 US
2.75 mm2 US
3.25 mm3 US
3.5 mm4 US
3.75 mm5 US
4 mm6 US
4.5 mm7 US
5 mm8 US
5.5 mm9 US
6 mm10 US
6.5 mm10.5 US
8 mm11 US
9 mm13 US
10 mm15 US
US to mm conversion table
US to mm conversion table
USmm
1 US2.25 mm
2 US2.75 mm
3 US3.25 mm
4 US3.5 mm
5 US3.75 mm
6 US4 mm
7 US4.5 mm
8 US5 mm
9 US5.5 mm
10 US6 mm
10.5 US6.5 mm
11 US8 mm
13 US9 mm
15 US10 mm

Quick answers

Quick answers

How many US is 10 mm?
10 mm is 15 US.
How many US is 6 mm?
6 mm is 10 US.

The units

About these units

Millimeters (mm)

The diameter of the shaft.

US numbers (US)

The number after the letter, from 1 to 15.

Learn more about hook size units

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