Finished knit doesn't fit? Here's how to make a sweater bigger

If your finished sweater is too narrow, don't worry – fixing it is easier than you think. Faye Perriam-Reed explains how.

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Faye Perriam-Reed

Published: April 22, 2025 at 1:13 pm

If your completed project has turned out a bit too narrow, we can help you fix it! In this tutorial, Faye Perriam-Reed shows you how to make a sweater bigger by widening the body and sleeves of your knitted garment.

Before you begin, undo the side seams of your sweater, and block any garment pieces if required following our how to block knitted garments guide.

Bear in mind that any width added to the body will also need to be added to the sleeve (and vice versa) in order for the sleeve cap to fit in to the armhole.

For example, if width is added to the body only, the armhole will be too wide for the original sleeve to fit into. If both the sleeves and the body on the original garment are too narrow, then a strip the same width can simply be added to both pieces. However, if only the body or the sleeve needs to be adjusted, a gusset will need to be added to taper the extra panel down to nothing on the adjacent piece.

By using our diagrams below, first choose your preferred style to add the necessary width, before working one of the following methods to knit the additional stitches.

How to make a sweater bigger: 3 knitting techniques

Step 1

Method 1: Adding width to the body, along with a tapered gusset at the armhole.

Adding width method 1, how to make a sweater bigger

Step 2

Method 2: Adding a straight strip to both the body and sleeve.

Adding width method 2, how to make a sweater bigger

Step 3

Method 3: Enlarging the armhole and sleeve with a gusset.

Adding width method 3, how to make a sweater bigger

Knitting at right angles to the work

Step 1

By picking up stitches down the side of the garment, you can add a panel worked perpendicular to the original knitting.

With RS facing, pick up two stitches for every three rows along the side seam and work in stocking stitch in rows until the desired extra width is complete. Work the same for both front and back, and then Kitchener stitch or sew the two sides together.

Note if you are using this method for the sleeves, you’ll need to use short rows to create a tapered gusset, so you might prefer to try one of the following methods instead if that isn’t for you.

Adding width step 4, how to make a sweater bigger

Knitting on a parallel section

Step 1

This technique involves casting on the number of stitches required to produce the extra width. The stitches are then knitted back and forth and joined to the original piece every other row as you go along.

To work a strip on to the right-hand side of the original knitting, work as follows:

Cast on one stitch more than the number of stitches needed for the desired width, using the cable cast-on method.

Knit across the new stitches until one stitch remains, slip this stitch knitwise. Insert the needle tip into the first stitch of the original knitting, pick up a stitch and pass the slipped stitch over it. Turn the work and knit to the end of the cast-off stitches.

Adding width step 5, how to make a sweater bigger

Step 2

Keep repeating the previous step until the new strip measures the same length as the original piece of knitting, then cast off. Make sure that on every joining row you are working in to every second row on the original knitting, not every row, to maintain the right tension.

If you are working a strip on to the left-hand side of the original piece, cast on the same number of stitches as for the right side and work two rows. *With the WS facing, pick up and purl one stitch in the last stitch of the original piece, turn the work so the RS is facing, K2tog, work to end of row. Repeat from * until the new strip measures the same length as the original piece of knitting, then cast off.

To work a tapered sleeve gusset, work in the same way along the desired length of the sleeve seam, decreasing every few rows (depending on the length of gusset required) until only two or three stitches remain. Fasten off.

Adding width step 6, how to make a sweater bigger

Picking up the stitches first

Step 1

Your work might be neater if you pick up and knit all the stitches along the side seam before you begin knitting a new strip. This way, you can ensure every stitch is picked up along the same column of stitches, resulting in a more consistent finish.

With RS facing, pick up one stitch in every other row along the side seam edge and knit across the WS row. Here we are using a contrast yarn for clarity.

Adding width step 7, how to make a sweater bigger

Step 2

Cast on one stitch more than the number of stitches needed for the desired width on to the needle holding the picked-up sts, using the cable cast-on method.

Adding width step 8, how to make a sweater bigger

Step 3

Work across the new stitches until one stitch remains, slip one knitwise, pass slipped stitch over. Adding width step 9, how to make a sweater bigger

Step 4

Turn the work and work to the end of the row.

Adding width step 10, how to make a sweater bigger

Step 5

Keep repeating steps 3 and 4 until the new strip measures the same as the original piece, then cast off.

Adding width step 11, how to make a sweater bigger

To work a strip on to the left-hand side of the work, follow step 1 above, then work from the top to the bottom to form the new piece.

Work a tapered sleeve gusset as for Knitting on a Parallel Section, picking up the desired amount of stitches to create the gusset length first.

Discover how to make a sweater bigger

Don't despair if your completed sweater is a little small – with these techniques you can add width to finished knitting and get a fit that's just right.

And with three different techniques to choose from, you can pick the one that works best for you too!

Keep your knits in perfect condition

Is your favourite sweater showing signs of wear? Find out how to mend your finished knits with our guide to darning.

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Faye Perriam-Reed

Knitting Designer & Technical Editor

Faye Perriam-Reed is a knitwear designer and technical editor, having worked and designed for both The Knitter and Simply Knitting. She enjoys exploring construction and finishing techniques to achieve neater results.