Yarn Weight Converter

Select a yarn weight category to instantly see WPI range, ply equivalents, and recommended knitting needle and crochet hook sizes.

Select Yarn Weight

Choose a category or enter your WPI count to identify your yarn.

Select a weight category or enter a WPI count to see the full specification.

Full Yarn Weight Reference Table

Click any row to load its details on the left.

# Name WPI Ply Needle (US) Needle (mm) Hook (US) Hook (mm)

Summary

Select a yarn weight category to instantly see WPI range, ply equivalents, and recommended knitting needle and crochet hook sizes.

How it works

  1. Select a yarn weight category from the dropdown or click one in the reference table.
  2. The tool instantly shows the WPI (wraps per inch) range for that weight.
  3. Ply equivalents (2-ply, 4-ply, 8-ply, etc.) are displayed alongside.
  4. Recommended US and metric knitting needle sizes appear in the results.
  5. Recommended crochet hook sizes (US letter and metric mm) are also shown.
  6. Use the full reference table below to compare all weights side by side.

Use cases

  • Identify the weight of an unlabeled yarn by counting wraps per inch.
  • Find substitute yarns in a different weight category for a pattern.
  • Determine the correct needle or hook size when starting a new project.
  • Convert between US, UK, and Australian yarn weight naming conventions.
  • Quickly reference ply equivalents when shopping for yarn internationally.
  • Check compatible hook sizes before swatching a new crochet project.
  • Teach beginners how yarn weight categories map to needle and hook sizes.
  • Confirm that a yarn label matches the weight called for in a pattern.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu