What this calculator does
Every knitting and crochet project depends on gauge. Once you know how many stitches and rows your yarn and needles make in a 4 inch swatch, you can work out any size: a scarf, a blanket, the front of a sweater. This calculator does that conversion and rounds the cast-on to a stitch count that suits your stitch pattern, then tells you the width that count actually gives.
How to use it
- Knit or crochet a swatch, block it, and count stitches and rows over 4 inches.
- Enter the finished width and length you want.
- If your stitch pattern repeats, open "Stitch pattern multiple" and enter it.
- Cast on the number shown and work the number of rows shown.
The math
stitches per inch = swatch stitches ÷ swatch width
cast on = width × stitches per inch, rounded
rows = length × rows per inch
With 20 stitches and 28 rows over 4 inches, you get 5 stitches and 7 rows per inch. A 20 inch wide piece needs 100 stitches, and 24 inches long is 168 rows.
Typical gauge by yarn weight
From the Craft Yarn Council's Standard Yarn Weight System, stockinette over 4 inches. Use it as a starting point; your own swatch always wins.
| # | Weight | Also called | Knit gauge | Needles |
|---|---|---|---|---|
| 0 | Lace | Fingering, 10-count crochet thread | 33–40 sts | 1.5–2.25 mm (US 000–1) |
| 1 | Super Fine | Sock, fingering, baby | 27–32 sts | 2.25–3.25 mm (US 1–3) |
| 2 | Fine | Sport, baby | 23–26 sts | 3.25–3.75 mm (US 3–5) |
| 3 | Light | DK, light worsted | 21–24 sts | 3.75–4.5 mm (US 5–7) |
| 4 | Medium | Worsted, afghan, aran | 16–20 sts | 4.5–5.5 mm (US 7–9) |
| 5 | Bulky | Chunky, craft, rug | 12–15 sts | 5.5–8 mm (US 9–11) |
| 6 | Super Bulky | Super bulky, roving | 7–11 sts | 8–12.75 mm (US 11–17) |
| 7 | Jumbo | Jumbo, roving | 6 sts and fewer | 12.75 mm and up (US 17+) |
Block the swatch. Many yarns grow or shrink when washed. Measuring an unwashed swatch is the most common reason a finished piece comes out the wrong size.
Questions people ask
What is gauge?
Gauge (tension in the UK) is how many stitches and rows fit in a set width, usually 4 inches or 10 cm. Knit a swatch at least 6 inches square in your pattern stitch, wash and dry it the way you will treat the finished piece, then count in the middle.
What if my gauge does not match the pattern?
More stitches per 4 inches than the pattern means your fabric is tighter: go up a needle size. Fewer means it is looser: go down a size. Or keep your needles and use this calculator to adjust the stitch counts.
What are the multiple and plus boxes for?
Stitch patterns repeat over a set number of stitches. Ribbing in K2, P2 needs a multiple of 4, and a pattern written as "multiple of 6 plus 2" needs 6 × something + 2. The calculator rounds your cast-on to the nearest count that fits.
Does this work for crochet?
Yes. Enter stitches and rows from your crochet swatch and read the cast-on count as the number of stitches in your first row. Add the turning chain your stitch needs to your foundation chain.