Knitting Needle Size Conversion

Knitting needle size conversion is handy when learning how to knit. Understanding knitting needles is one of the first hurdles of knitting. Knitting patterns usually indicate the size of the knitting needle or needles you need to complete the project.

Depending on where the pattern originates, it may give you the size of a metric, UK or US needle. This can be confusing.

Knitting Needle Size Conversion

It would be so much easier if there were standard knitting needle sizes. Why does there have to be a difference? To make things easier for you, we have created a knitting needle size conversion chart.  

Does Knitting Needle Size Matter?

knitting needle size

In some instances, the size of the knitting needle does not matter. For something like a scarf, you can use a knitting needle that is a size smaller or a size bigger. But if you are making a sweater or a dress, the knitting needle size does matter.

If you use a different size knitting needle than what the pattern calls for, the size of the finished pattern will be affected. The size of the needle influences the gauge of the stitches. The yarn weight and type of yarn you use will also change the outcome.

What Happens if I Use the Wrong Size Needle?

knitting needle conversion

Using a smaller knitting needle than what is required will result in smaller stitches. The smaller stitches will result in tighter and denser fabric. Small needles are often used when there is a detailed pattern.

Using a larger knitting needle will create larger stitches. The larger stitches will create a looser fabric. Large needles are often used to create texture and movement.

Knitting Needle Conversion Chart

Below is a list of the most common knitting needle sizes. We have included metric, US, and UK measurements in our knitting needle size conversion chart.

This knitting needle conversion chart is a useful tool in your knitting journey.

MetricUS Size / AmericanUK Size / Imperial
2.00 mm014
2.25 mm113
2.50 mm1.5N/A
2.75 mm212
3.00 mm2.511
3.25 mm310
3.50 mm4N/A
3.75 mm59
4.00 mm86
4.50 mm77
5.50 mm95
6.00 mm104
6.50 mm10.53
7.00 mmN/A2
7.50 mmN/A1
8.00 mm110
9.00 mm1300
10.00 mm15000
12.00 mm17N/A
16.00 mm19N/A
19.00 mm35N/A
20.00 mm36N/A
25.00 mm50N/A

What Size Knitting Needle Do You Have?

knitting needle conversion

Newer knitting needles usually have the size on the end of the needle. But if the size is missing, how do you know what size needle you have? There is a handy little tool called a knitting needle gauge that will help you determine your needle size.

A knitting needle gauge is a flat notion that has several holes in it. Most gauges have US and metric sizes. Each hole is marked with the appropriate size. Simply slip your needle through the holes and find the best fit.

Knitting needle gauge

If the hole is too large, try the next size down. If the hole is too small, try the next size up. The needle should slide through the hole with no wiggle room.

Most knitting needle gauges are combined with a knitting gauge ruler. The ruler is handing for measuring the gauge of your knitting.

Please note the sizes of knitting needle gauges can vary slightly. The manufacturer determines the actual size of the needle.


If you are new to knitting and looking for patterns, check out our Scarf Patterns for beginners and Knit Hat Patterns for beginners. We also have tutorials on How to Basket Weave Stitch and Kitchener Stitch Tutorial for beginners.

Knitting would be so much easier if there was a standard for needle sizes. But that is not the case. We hope that our knitting needle size conversion chart will help you in your knitting journey.     

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