Free Knitting Needle Size Converter

Knitting needle sizes vary by country — US, UK, and Japanese systems all use different numbers for the same needle. Use this converter to find the exact metric (mm) equivalent across all systems.

Knitting Needle Size Converter

Select a size to see conversions

Complete Size Reference Chart

Metric (mm) US UK (old) Japanese Used In
2 mm 0 14 0 US · UK · JP · Europe
Russia · China · India · AU/NZ
2.25 mm 1 13 1 US · UK · JP · Europe
Russia · China · India · AU/NZ
2.75 mm 2 12 2 US · UK · JP · Europe
Russia · China · India · AU/NZ
3 mm 11 UK · Europe
Russia · China · India · AU/NZ
3.25 mm 3 10 3 US · UK · JP · Europe
Russia · China · India · AU/NZ
3.50 mm 4 4 US · JP · Europe
Russia · China · India · AU/NZ
3.75 mm 5 9 5 US · UK · JP · Europe
Russia · China · India · AU/NZ
4 mm 6 8 6 US · UK · JP · Europe
Russia · China · India · AU/NZ
4.50 mm 7 7 7 US · UK · JP · Europe
Russia · China · India · AU/NZ
5 mm 8 6 8 US · UK · JP · Europe
Russia · China · India · AU/NZ
5.50 mm 9 5 9 US · UK · JP · Europe
Russia · China · India · AU/NZ
6 mm 10 4 10 US · UK · JP · Europe
Russia · China · India · AU/NZ
6.50 mm 10.5 3 US · UK · Europe
Russia · China · India · AU/NZ
7 mm 11 2 11 US · UK · JP · Europe
Russia · China · India · AU/NZ
7.50 mm 1 UK · Europe
Russia · China · India · AU/NZ
8 mm 13 0 12 US · UK · JP · Europe
Russia · China · India · AU/NZ
8.50 mm 00 UK · Europe
Russia · China · India · AU/NZ
9 mm 15 000 13 US · UK · JP · Europe
Russia · China · India · AU/NZ
10 mm 17 14 US · JP · Europe
Russia · China · India · AU/NZ
20 mm 35 US · Europe
Russia · China · India · AU/NZ
25 mm 50 US · Europe
Russia · China · India · AU/NZ

About the Knitting Needle Size Converter

A knitting needle size converter translates between US, UK, Japanese, and metric sizing systems. International patterns often list sizes differently — this tool eliminates confusion so you always use the correct needle.

Quick Start Guide

  1. Enter your values — Fill in the fields with numbers relevant to your knitting needle size calculation. Most fields include sensible defaults.
  2. Adjust settings — Change options like units, rates, or timeframes to match your specific scenario.
  3. Review results — The output shows a clear breakdown so you understand how the total was calculated.

How It Works

Maps needle sizes across US (0-50), UK (14-000), Japanese (0-15), and metric (1.0mm-25.0mm) systems using standard conversion tables. Includes a complete reference chart for all sizes.

Real-World Example

Scenario: Following a UK knitting pattern in the US

  1. Pattern calls for: UK Size 7.
  2. US equivalent: US Size 6.
  3. Metric equivalent: 4.0 mm.
Result: UK Size 7 = US Size 6 = 4.0 mm. Always knit a gauge swatch to verify your tension matches the pattern — needle size is a starting point, not a guarantee.

Who Is This For?

This knitting needle size converter is designed for Students, professionals, and anyone who needs quick, accurate conversions and calculations for everyday tasks.. It's intentionally simple — no complex signup forms, no data tracking, no distractions. Just enter your numbers and get the answer.

Pro Tip

Bookmark this tool for quick access — you will use it more often than you think.

Things to Know

The knitting needle size converter provides instant, accurate results based on standard formulas and the values you enter. Whether you are planning a financial decision, tracking a health metric, or solving a practical problem, this tool gives you the numbers you need without requiring signup or account creation.

How to get the best results: Use accurate, up-to-date inputs for the most reliable calculations. When planning ahead, run multiple scenarios with different assumptions to understand the range of possible outcomes.

Note: This tool is designed for educational and planning purposes. For critical financial, medical, or legal decisions, always verify the results with a qualified professional who can evaluate your specific circumstances.

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Frequently Asked Questions

Is there a limit on how many times I can use this?

No limits at all. Use it as many times as you need, completely free.

Does this work on mobile devices?

Yes. The tool is fully responsive and works on smartphones, tablets, and desktop browsers.

How accurate are the results?

Results are based on standard formulas and the values you enter. They are accurate for educational and planning purposes.

Is this tool really free?

Yes, completely free. No signup, no hidden charges, no usage limits. Use it as often as you need.

Can I share the results?

Yes. You can take a screenshot or share the page link with anyone. The tool works the same for everyone.