Originally from Scotland, Jenny Rushmore is a curvy sewing blogger who traveled the world and now lives in Boston, Massachusetts. Since she learned to sew at the “ripe old age of 30,” Jenny has been blogging at Cashmerette. Last year Jenny co-founded the Curvy Sewing Collective, a site dedicated to sewing inspiration, advice and body positivity for curvy women. Sewing transformed Jenny’s body image, and now she’s passionate about sharing that experience with others. Jenny is one of our Super Online Sewing Match judges!

Her latest venture is the release of the Cashmerette Curvy Sketchbooks, a line of sketchbooks with curvy figure outlines to help sewists and fashion designers plan their next make, and record notes on things like adjustments they made.

Jenny is here to show you just how easy it is to expand the waist on a sewing pattern! There are just a few simple steps for a better fit, every time.

How to Expand the Waist on a Sewing Pattern

From Jenny Rushmore of Cashmerette

Do you ever find that you can fit in a skirt or pants sewing pattern, but realize the waist is going to be just a bit too small? Luckily it’s easy to expand the waist in a few easy steps so you can end up with a perfectly fitting garment!

1. Calculate how much extra width you need to add to the waist.

  • Measure your waistline with a tape measure, and compare that to the finished garment waist measurement of the pattern. Calculate how much you’ll need to add to the waist by subtracting the finished garment measurement from your waist measurement, adding ease (1/2 inch to 1 inch is common), then dividing by 4 (as we’ll be adding a little to the front and back on each side). So for instance, if my waist is 40 inches and the garment waist is 37 inches, and I want 1 inch ease, then my calculation is: (40 – 37 +1)/4 = 1 inch.

2. Draw in seam allowances.

  • Start by drawing in the seam allowance on the front pattern piece of your skirt or pants. Mark along the waist and hip, to about 6 inches down.

3. Draw diagonal line 1.

  • Draw a diagonal line from the hip about 6 inches down, to the waistline. Don’t worry too much about the exact angle; it doesn’t matter!

4. Draw diagonal line 2.

  • Now, draw another diagonal line from the corner of the waist and sideseam down to meet the first line at about a 90 degree angle.

5. Cut and spread your pieces.

  • Cut down the first diagonal line, starting at the waistline and finishing at the seam allowance at the side seam. Then make a little cut into the seam allowance on the other side, to form a hinge. Carefully spread open the piece, making sure the hinge stays intact.

  • Cut up the second diagonal line, starting where it meets the first line, out until you reach the seam allowance at the corner. Again, make a little cut into the seam allowance on the other side, forming a hinge.
  • Carefully slide the small triangle at the top down, to make the waistline even. Adjust the pieces so that you’re adding the required amount of width at the waistline (what you calculated in Step 1).

6. Trace your final pattern piece.

  • Lay a piece of tracing paper over your adjusted piece and re-trace your new pattern piece, smoothing out the hip curve and joining the waistline.

7. Adjust your back piece, and any pockets or waistband.

  • Now, repeat the same process on your back skirt or pants piece! Remember, if you have slash pockets or a waistband or facing, you’ll also need to add the additional width to those pieces.