I've coached hundreds of knitters through their first sweater, and the same mistake comes up over and over: skipping the gauge swatch.

Here's what actually happens when you skip it:

Say your pattern calls for 18 stitches = 4 inches in worsted weight. You cast on, knit for weeks, try it on — and it's either a tent or a straitjacket. The math was right. Your tension wasn't.

The fix takes 30 minutes:

1. Cast on 24+ stitches in your project yarn

2. Knit in stockinette for at least 4 inches

3. Bind off loosely, wash it exactly how you'll wash the sweater, lay flat to dry

4. Measure the center 4" square — ignore the edges, they curl and lie

If you're getting 20 sts/4" instead of 18, go up a needle size. Getting 16? Go down. Repeat until the numbers match.

Pro tip: Your gauge in the round is almost always different from flat. If your sweater is knit in the round, swatch in the round. Cut the swatch open to measure if needed.

This one step is the difference between a sweater that fits and an expensive dishcloth. Trust me on this.

— Knitwise Studio

I've coached hundreds of knitters through their first sweater, and the same mistake comes up over and over: skipping the gauge swatch.

Here's what actually happens when you skip it:

Say your pattern calls for 18 stitches = 4 inches in worsted weight. You cast on, knit for weeks, try it on — and it's either a tent or a straitjacket. The math was right. Your tension wasn't.

The fix takes 30 minutes:

1. Cast on 24+ stitches in your project yarn

2. Knit in stockinette for at least 4 inches

3. Bind off loosely, wash it exactly how you'll wash the sweater, lay flat to dry

4. Measure the center 4" square — ignore the edges, they curl and lie

If you're getting 20 sts/4" instead of 18, go up a needle size. Getting 16? Go down. Repeat until the numbers match.

Pro tip: Your gauge in the round is almost always different from flat. If your sweater is knit in the round, swatch in the round. Cut the swatch open to measure if needed.

This one step is the difference between a sweater that fits and an expensive dishcloth. Trust me on this.

— Knitwise Studio