Two people can follow the same pattern with the same yarn and the same hook and end up with garments two sizes apart. The difference is gauge, and it is the one step almost everyone skips.
What gauge means
Gauge is how many stitches and rows you get in a given measurement — usually 4 inches or 10 cm, though patterns vary. Our Rib Stitch Cardigan, for instance, is written to 24 rib stitches and 20 rows over 5 by 5 inches.
Your personal tension — how tightly you hold the yarn — is what makes your gauge differ from the designer's. It isn't something to fix. It's something to measure and then compensate for with hook size.
Why it compounds
Say the pattern wants 16 stitches to 4 inches and you're getting 15. That's a difference of one stitch — nothing, surely.
Across a 200-stitch cardigan front, that one stitch per four inches makes the piece about 3 inches wider than intended. Both fronts and the back, and you've added the best part of 6 to 8 inches to the finished garment. That's how a small becomes a large.
The error is small per inch and enormous per garment. That's the whole story.
Measuring it properly
- Make the swatch bigger than the measurement. For a 4-inch measurement, crochet at least 6 inches square. Edge stitches are always a different tension and you need to measure away from them.
- Use the stitch pattern the pattern uses. A double crochet swatch tells you nothing about a project worked in rib stitch or granny squares.
- Block it the way you'll wash the finished thing. Some yarns shift noticeably after their first soak. Measuring unblocked and then blocking the garment is measuring the wrong fabric.
- Lay it flat and don't stretch it. Measure in the middle, count the stitches across 4 inches and the rows down 4 inches. Count partial stitches as partials — 15.5 is a real and useful answer.
What to change when it's off
- Too many stitches per 4 inches — your stitches are smaller than the designer's. Go up a hook size.
- Too few stitches per 4 inches — your stitches are bigger. Go down a hook size.
Change the hook, never your tension. Crocheting deliberately tighter or looser than is natural to you is impossible to sustain over thousands of stitches, and the garment will drift back to your real tension somewhere around the second sleeve.
Swatch again after changing. A half-size hook is often all it takes.
Stitch gauge matters more than row gauge
If you can only match one, match stitches. Stitch gauge controls width, and width is what decides whether a garment fits.
Row gauge controls length, which is usually easy to adjust — work more or fewer rows until the piece measures what the pattern says in inches. Most well-written garment patterns give lengths in measurements for exactly this reason.
When gauge genuinely doesn't matter
- Amigurumi. Nobody cares if a teddy is half an inch taller. All that matters is that the fabric is dense enough to hide the stuffing — see choosing yarn for amigurumi.
- Blankets, scarves and bags. Slightly bigger or smaller is simply slightly bigger or smaller. Keep an eye on yarn quantities though — a looser gauge eats more yarn than you budgeted.
- Anything you'll measure as you go rather than following a stitch count.
So: swatch for anything that has to fit a body, and don't bother for anything that doesn't.
The fifteen minutes
A swatch takes about fifteen minutes. A cardigan takes weeks. It's the best odds you'll ever get in this craft.
If you're starting a garment, our tops and cardigans patterns all list gauge and full finished measurements up front, so you can check before you buy the yarn rather than after.