Have you found a pattern that you’re keen to get started with, but it asks for 3.25mm knitting needles ( or any other size for the purposes of this post), and you are not quite sure which needle size that means? It’s crucial to use the right size needle, especially if you are making a fitted garment, so it’s important to understand how the sizing system works.
In this post, I have included a knitting needle conversion chart, which will help you get it right. Bookmark this page to find it later.
Some patterns might include all the different sizes in brackets, but sometimes they will only have one mentioned, so it is a good idea to be aware and to know what the sizes mean.
The type of wool used will also affect your needle size, and that will also give you a clue as to what ballpark size you should be using. The yarn label usually recommends a needle size, too.
3 Main Conventions for Needle Sizing
There are broadly 3 main conventions for naming of knitting needle sizes.
- Metric mm system
- UK sizing
- USA sizing
There are more conventions to name needles, but these are the main ones – for example the Japanese also have a different system for naming.
Metric System
This naming system lists the needle sizes by their thickness in millimetres (mm). This is easy to grasp, but sometimes you might pick up a needle that has no size written on it. You could, of course, use a knitting needle gauge measuring tool to find out what the size is.
UK & Canada Sizing of Knitting Needles
These countries use a numbering system for describing needles such that a higher number for example, a 14 means a smaller diameter needle. In the case of a UK 14, this is a 2mm diameter needle. At the other end of the scale, a 0 UK-sized needle is an 8mm diameter needle.
USA Naming System for Knitting Needles
The USA naming convention is completely the opposite to the UK/Canada’s one as smaller diameters start with low numbers, for example, a USA 0 needle has a thickness of 2mm, and an 8mm needle is called a number 11 in the US.
Confusing Naming Systems? Yes Definitely!
The numbering systems are somewhat confusing, so it is best to keep a conversion chart nearby and/or a needle gauge just to check that you have the right needle.
AFFILIATE DISCLAIMER
Disclosure: This post may contain affiliate links for products recommended. This means that if you click a link and buy something I may receive some compensation, but this is at no cost to you the reader. Thank you for visiting this website.
This product has the metric mm sizes on one side and the US sizes on the reverse side. You can also choose between a cat, dog or sheep design.
These little tools are easy to use; just slide your needle into the little holes until you find one that fits smoothly all the way through.
Summary
- Different naming conventions exist for different parts of the world
- 3 main ones are the metric – actual mm thickness, USA and Canada/UK systems
- USA numbering system starts from 0 (2mm) and goes to 50 (25mm)
- Canada/UK numbering system starts from 14 (2mm) and goes to 000 (10 mm)
- Useful to invest in a knitting needle gauge measuring tool
For more useful knitting equipment, visit the Equipment category
