Knitting Needle Sizes Explained: A NZ Guide
The right size.
The right shape.
Ready to cast on.
Make sense of millimetres, straight and circular needles, tips and cables before choosing your tools.
Millimetres describe the needle shaft’s diameter. Cable length is a separate measurement.
A “size 8” can
mean different things.
Check which sizing system your pattern uses. Metric sizes state diameter in millimetres; US and older UK numbering are different systems. Use the marked millimetres on the tool or packaging to avoid confusion.
| Metric diameter | US knitting size |
|---|---|
| 3.25mm | 3 |
| 3.5mm | 4 |
| 3.75mm | 5 |
| 4mm | 6 |
| 4.5mm | 7 |
| 5mm | 8 |
| 5.5mm | 9 |
| 6mm | 10 |
| 6.5mm | 10½ |
| 8mm | 11 |
The metric size is your check.
These are selected common pairings from the Craft Yarn Council reference, not a complete conversion chart. Some number labels cover more than one diameter; follow the actual mm measurement.
This table is for knitting needles. Crochet hooks have their own letter and number conventions.
What if the needle size has rubbed off?
Use a knitting needle gauge to identify the shaft diameter, then compare it with your pattern. Do not judge the size by the point alone.
Choose the tool
for the way you knit.
Flat or in the round?
Check the pattern’s construction as well as its diameter requirements. A jumper might need a main needle size, a smaller size for edges and separate tools for small circumferences.
Choose the pattern first if you are unsure. Its materials list gives a much clearer starting point than a generic needle recommendation.
Explore patterns with project builders →Straight needles
A pair of straight needles suits work knitted back and forth when the stitches fit comfortably on the needles. Choose the diameter and length required for the pattern.
Fixed circular needles
Two tips joined by a fixed cable can be used for working in the round or back and forth. For ordinary circular knitting, choose a total length that suits the circumference; magic loop uses a different, longer-cable approach.
Shop circular needles →Interchangeable needles
Separate tips attach to compatible cables, letting you change the combination. Check the brand, range, connection size and tip length before choosing a cable.
Shop interchangeable needles →Double-pointed needles
DPNs come in sets and are commonly used for small circumferences. Follow the pattern’s size and method, or choose a different method only if you know how to adapt it.
Shop double-pointed needles →Same diameter.
A different length and feel.
Millimetres describe thickness; centimetres describe length. A 4mm needle can be short or long. Choose the diameter your pattern and tension swatch require, then choose a length that suits the construction, stitch count and your hands.
10cm or 13cm interchangeable tips?
10cm · Short / Special tips
A shorter handhold allows compact circular setups. KnitPro pairs its 10cm Special tips with cables labelled to make 40cm or 50cm finished circulars—useful for hats, necklines and other pieces whose circumference suits that length.
Short tips can also be used with longer compatible cables. They are not limited to small projects; the grip simply feels different.
Shop Zing 10cm Special tips →13cm · Standard / Normal tips
More shaft length gives a fuller handhold. KnitPro's 13cm Normal tips are intended mainly for 60cm and longer finished circulars, for suitable garment rounds or work knitted flat.
Do not choose standard tips for a short setup just because the threads connect. Long rigid tips leave less flexible cable to curve between your hands.
Shop Zing 13cm Normal tips →These are KnitPro examples, not universal rules for every brand. Check the specific range's connection and length convention. Changing the tip length on the same cable changes the finished length. A 40cm circular will not fit every small tube: socks, narrow cuffs and hat-crown decreases may need DPNs, a suitable mini system or a loop technique.
30cm or 35cm straight needles?
30cm · A more compact pair
A useful choice when the stitches fit comfortably and you prefer less needle length to manage. Consider your grip and knitting style as well as the project width.
Shop Symfonie 30cm straights →35cm · More room for stitches
The extra shaft length provides more room for wider pieces, with a longer needle to handle. Some knitters also prefer that length for the way they support their needles.
Shop Symfonie 35cm straights →There is no fixed stitch capacity for either length: yarn thickness, needle diameter and how the stitches sit all matter. A 35cm needle does not limit you to a 35cm-wide finished piece. For wide or heavy flat knitting, a suitable circular needle can carry the stitches on its cable while you work back and forth.
Does changing the length change my needle size?
No—a 4mm needle remains 4mm in diameter whether it is a 10cm interchangeable tip or a 35cm straight needle. Length affects handling and which setups are practical. Your personal tension can still change with different tools, so check a swatch when switching.
Manufacturer reference: KnitPro catalogue: tip lengths, circular sets and straight needles. Diagrams show relative lengths within each pair; they are not life-size.
Tips need cables.
Cables need compatibility.
-
Check what the listing includes.
Replacement tips, standalone cables and complete needle sets are different purchases. Read the contents before adding them to your basket.
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Match the connection.
Do not assume cables interchange across brands or even across every range within one brand. Match the manufacturer’s compatibility information.
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Check how length is described.
A cable may be labelled by the finished circular-needle length it creates with a particular tip, rather than the cable alone. Check the listing’s stated convention and the tip length it assumes.
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Review every size in your pattern.
Your main fabric and ribbing may use different diameters. Check you have all the tips, cables or other needles required for your chosen construction.
Let your swatch
confirm the choice.
Measure the number of stitches and rows over the area specified in your pattern, in the stated stitch and after any instructed washing or blocking.
More stitches than required over the same width usually calls for a larger needle; fewer usually calls for a smaller one. Swatch again and check both tension and the resulting fabric.
Changing needle material or working flat instead of in the round can affect your personal tension. Test using the tools and method intended for the project.
Finish planning your project.
Calculate your yarn quantity →
Ask us about a specific needle and cable combination →
Include the brand, needle range, tip diameter and desired total length so we can help check the right combination.