Cast-on and foundation chain calculator

How it works

Your gauge tells you how many stitches fit into 4 inches (or 10 cm). Divide to get stitches per inch, then multiply by the width you want:

stitches = (width + ease) × (gauge stitches ÷ 4)
Example: 20 in × (20 ÷ 4) = 100 stitches

If your stitch pattern repeats over a set number of stitches, the count has to fit that repeat. The calculator gives the nearest counts either side and the width each one will actually knit or crochet up to, so you can pick the one closest to your plan.

Measuring gauge

• Make a swatch at least 6 in (15 cm) square in the stitch pattern you'll use, with the needles or hook you'll use.
• Wash and block it the way you'll treat the finished piece, then let it dry.
• Count stitches over 4 in (10 cm) in the middle, away from the edges. Include half stitches: they add up across a whole piece.

Ease in a nutshell

Ease is the difference between the finished piece and the body it fits. Positive ease makes a relaxed fit, like a roomy sweater. Negative ease makes a piece that stretches to fit, like a hat or socks. Leave it at 0 for things like scarves and blankets.

For crochet

The result is the number of stitches in your first row. For the foundation chain, chain that many plus your turning chain. Patterns often use 1 extra chain for single crochet, 2 for half double and 3 for double crochet, but follow your pattern if it says otherwise.