Advanced Swatching: Adjusting Your Size

Swatching is absolutely necessary before knitting fitted garments. There are many reasons to swatch, which are covered in our basic swatching tutorial, Calculating Gauge in Knitting. In this tutorial, we explore how to use your swatch to customize a garment to your size.

Customize Your Garment

Knowing how to make simple adjustments to your patterns allows you to customize any pattern to fit you perfectly. Learning how to adjust the overall size of a garment is the first step to customizing a pattern.

This is handy to know if:

  • You are between sizes
  • You’re not happy with the fabric that you created with the recommended gauge
  • You want to use a different size yarn than what the pattern was written for.

Start by swatching as recommended here. Even if you know how to knit a swatch, you might want to check it out to see how I “record” the needle size I used right in the swatch so I never forget which size I used to knit that swatch.

To show you how to determine the final size of your garment based on your swatch, I’m using my actual calculations for the Cinnamon Girl Cardigan. The stated gauge in that pattern is 16 sts & 22 rows in 4” blocked.

After blocking, my swatch gauge is 15.5 sts & 22 rows in 4”, so my stitches are ever so slightly larger than the pattern gauge.

I’m going to go with it since the 44.5” size is about 1” smaller than I’d like. My larger stitches should make up the difference. If my calculations are correct, I should end up with a 45.9” sweater. Perfect!

Here’s how I calculated my final size:
  • Explanation – Follow these steps:
    1. Choose the size in the pattern that you think you want to make.
    2. Multiply it by the # of sts in the pattern gauge. This gives you the total number of stitches.
    3. Divide the total number of stitches by the # of sts in your swatch. This gives you the finished size of your garment using your gauge when you follow the instructions for the size you chose in step 1.
  • The formula:
    • M=Measurement of the size you want to make, as stated in the pattern
    • G=# stitches in the pattern gauge
    • Y=# stitches in your swatch, measured over the distance specified in the pattern gauge (usually 4″ or 1″; in this case 4″)
    • Formula: M x G / Y = Finished size
  • My calculation: 44.5” x 16 sts / 15.5 sts = 45.9” finished size according to the size of the stitches in my swatch

If I wanted a smaller size, I would use the formula above to figure out what size mine would turn out if I followed the instructions for the 41” size. In that case my formula would be: 41 x 16 / 15.5 = 42.27” finished size. You can do the same thing for any size in the pattern.

Want More Help Figuring this Out?

Math can be confusing! Actually, a lot of things in a knitting pattern can be confusing. That’s why I started the Knit Along Club. Our lessons clarify the confusion so that you can knit your projects with confidence. And if you have a question not covered in the lessons, we can handle that too! Learn more or join today at

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