How to Alter a Sewing Pattern

By Aurora Sisneros

How to Alter a Sewing Pattern

We all know one of the most exciting parts about making a garment is picking out the fabric and cutting it all up in to pieces, but my advice to you is to be patient! First take a close look at your pattern – does it need to be altered?

Sometimes it can be difficult to make alterations to a dress that has already been made up in the beautiful fabric that you found for $20 a yard. Then, if it doesn’t fit quite properly, the disappointment can send it to your closet for several months before you can bear to tackle the altering.

Related Video: Sewing Pattern Alteration and Tools



Make friends with muslin
If I am making a dress or skirt and I want it to fit just right, I make one first in muslin. Muslin is between $1 and $3 a yard, so it’s not a huge investment to make a mock-up first to get the fit right. I always have a bolt on hand in my sewing room for just this purpose.

I am small busted so I always have to alter the darts in a bodice, but I have a hard time visualizing how they need to be changed in order to fit me. So, I make up the bodice in muslin, try it on inside out (so I have easy access to the seams), place some pins to cinch in the darts (and to get rid of that awful baggy chest look!), and firm everything up to be a perfect fit (with ease, of course!).

Creating a new pattern
Now that I have a better-fitting bodice with some room for movement, I can take it off and examine the new folds made from my pinning, and then sketch them in with an iron-off pen. Once I trim the bodice to be just how I want it to be, then that becomes my NEW pattern piece for this pattern! To make the pattern piece even stiffer and easier to work with when I want to make new versions of it in the future, I buy an inexpensive fusible interfacing and iron it to the back.

The other thing you can do for a good fit is get yourself a dress form. Some of the adjustable ones can be fussy to get them to match your exact measurements, but it definitely makes the muslin test easier to pin to get a better fit. If you’re not ready to invest in a professional dress form, there are some great tutorials online about how to make one custom-fit to your body using duct tape. Here’s my favorite.

Measure twice
Lastly, always double-check your work with math. When you are sewing a skirt, you usually have a front and a back pattern piece that are meant to be cut on the fold. Therefore, the waistline at the top of the skirt front is ¼ of your entire waist line! Measure your waist (or where you want the skirt to sit) and divide by 4. Then, add seam allowance. This is a quick way to make sure your alteration is in the ballpark!

Remember, there are no set rules on how to alter a sewing pattern. Feel free to experiment and add embellishments and seaming for visual interest! My advice to you however? Make friends with muslin and create yourself a new pattern altered to your measurements – especially before you cut into that beautiful silk!

Happy sewing!

Get in touch! Leave a comment or email editor@nationalsewingcircle.com.

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26 Responses to “How to Alter a Sewing Pattern”

  1. Jacqui

    The pants I made from scratch are a bit wide around the hip area. How do I alter this for the legs not to twist (side seam)?

  2. whitemarlece

    The videos are excellent !!! Thank you and keep up the good and very professional work

  3. myriam levi

    Hi. I'm a sewing teacher and I yused to use the full measurement chart of burda to do the exact fitting on my patterns. In the past 2 or 3 years you aliminated fue of the very important measures from the chart like bust depth , front length and back length. I wonder why you did it. For me and my students it is very missing. We keep using the old full chart... I would like to understand what was your consideration by changing it for bad. Thank you so much.

  4. kantha moodley

    topics are very

  5. Firoza

    Very interesting

  6. Doaa

    want to learn how to sew

  7. Maryna Maré

    Would like to join the group

  8. Jonalyn

    Please send me a steos on how to do alter thank you i really appreciate if somebody reply :)

  9. Cheryl

    Your videos confirmed my sewing instinct's, giving me the confidence to go out of my comfort zone and try adjusting my patterns for a better fit. I have a dress form but still needs some help, so loved the idea of a duct tape form. Why not splitting it to fit over my store bought form. Well I'm going to give it a try will let you know how it works. And the muslin idea is really a $ saver in the long run for plus sizes.

  10. Lindaflor Miller

    Hello. It has been a long time since I cut out a pants pattern and now I forgot how to do it. I forgot what the measurement I should use for the inside seem so the butt measurement is not too tight. How much allowance should I add on the unseen? Thank you in advance. I would appreciate it if you can give me some advise.