Quick answer: The long-tail cast on creates a neat, elastic edge by looping yarn over your thumb and index finger in a slingshot position and drawing a new stitch through on each repeat.
What it is
The long-tail cast on is one of the most popular cast ons in knitting. It's fast, creates a neat and elastic edge, and requires estimating a long tail before you start — roughly 1 cm per stitch, plus 15–20 cm extra. It creates a neat foundation row as you cast on, saving you a row of knitting.
When to use it
- General purpose: hats, sweaters, socks, shawls — works for almost any project
- When you want an elastic, stretch-friendly cast-on edge
- When you want a neat, consistent bottom edge without a separate foundation row
How to do it
- Make a slip knot, leaving a long tail (estimate 1 cm per stitch). Place the slip knot on your needle — this is stitch one.
- Hold the needle in your right hand. Drape the tail over your left thumb and the working yarn over your left index finger. Hold both ends in your palm.
- Spread thumb and index finger apart to create a slingshot V with the yarn.
- Insert the needle tip up through the loop around your thumb (from bottom to top).
- Bring the needle over and catch the yarn from your index finger, pulling it back through the thumb loop.
- Slide your thumb out of its loop and use it to snug the new stitch onto the needle.
- Repeat steps 3–6 for each additional stitch.
Common mistakes
- Running out of tail mid-cast-on — estimate more generously next time, or splice in extra tail yarn
- Twisting the stitch when inserting the needle — always enter the thumb loop from bottom to top
- Casting on too tightly — relax your thumb and index finger and let stitches sit loosely on the needle