Enter the gauge from your pattern and the gauge from your own swatch, and this tells you how far out you are as a percentage, which way to change hook, and how many hook sizes to move. It will also rewrite a stitch count if you would rather keep your hook and adjust the pattern. A half-millimetre hook step shifts gauge by roughly five to seven per cent.

What the pattern says:

Your swatch, measured in the middle and not at the edges:

How to use it

  1. Crochet a swatch at least six inches square in the stitch the pattern uses, with the hook and yarn you intend to use.
  2. Measure four inches across the middle and count the stitches. Never count the edges.
  3. Enter both gauges. Change hook in the direction shown and swatch again — do not try to change your tension by will.

A worked example

The pattern says 16 stitches to 4 inches. Your swatch gives 18 stitches to 4 inches, so you are at 4.5 stitches per inch against the pattern’s 4 — 12.5% tighter, and a 20″ wide blanket would finish at 17.8″. Go up two hook sizes, from 4.0mm to 5.0mm, and swatch again. Or keep the hook and work 225 stitches where the pattern says 200.

Crochet hook sizes and what a step does

Metric US Typical yarn weight
2.25 mm B/1 Lace, fingering
2.75 mm C/2 Fingering
3.25 mm D/3 Sport, amigurumi in worsted
3.5 mm E/4 Sport, DK
4.0 mm G/6 DK
4.5 mm 7 DK, worsted
5.0 mm H/8 Worsted
5.5 mm I/9 Worsted, Aran
6.0 mm J/10 Aran
6.5 mm K/10.5 Aran, bulky
8.0 mm L/11 Bulky
9.0 mm M/13 Super bulky

One step of half a millimetre changes gauge by about five to seven per cent. If you are more than fifteen per cent out, move two sizes rather than one.

Frequently asked questions

How do I fix crochet gauge that is too tight?
Go up a hook size and swatch again. Each half-millimetre step changes gauge by roughly five to seven per cent. Changing hook is far more reliable than trying to consciously loosen your tension, which never lasts past the first row.
Do I really need to make a gauge swatch?
For anything sized — a garment, a blanket to fit a bed, a hat — yes. For amigurumi, gauge matters less for size and more for density: too loose and the stuffing shows through the stitches.
How big should a gauge swatch be?
At least six inches square, so you can measure four inches in the middle and ignore the edges. Edge stitches always distort and measuring them is what makes swatches lie.
Why is my gauge different from the pattern with the same yarn?
Tension is personal — how you hold the yarn, how tight you pull each loop, even how relaxed you are. Two crocheters with identical hook and yarn routinely differ by a full hook size. That is normal and it is why swatches exist.
Should I match stitch gauge or row gauge?
Match stitch gauge first; it controls width, which is far harder to fix afterwards. Row gauge you can usually correct by working more or fewer rows to the stated length.

Related free tools

Yarn yardage calculator — how much yarn a substitution needs · Crochet increase calculator — spacing increases evenly · All free craft tools

Our crochet patterns give a gauge for every size and a stitch count on every round, so a swatch is all you need before starting.