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



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!).

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.

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 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!

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Discussion
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35 Responses to “How to Alter a Sewing Pattern”
  1. Virginia

    Your right and left sides are rarely exactly the same so be careful marking alterations by putting the muslin on wrong side out. It’s better to have someone who can mark them with the muslin on as it will be worn.

    Reply
    • Maureen

      When I do amuslin for the initial fit, I don’t turn in inside out as you are correct – we can be different issues from one side to another. I simply sew the seams and darts wrong sides together to pin and mark.

      Reply
  2. Filomena

    I love your videos, just that I would like to see a lot more. I would like to see how to serge with difficult fabrics, serging with bias cut fabric. I had a lot of problems when I did a rolled hem of a circle dress using my serger. It worked great until it started serging on the bias of the hem. It would not do the rolled hem. I later found out that all I had to do was use washable stabilizer. I would also like to see more videos that would help sew fabrics like leathers, stretch fabrics, fun fur.

    Reply
    • National Sewing Circle

      Hi, Filomena. We would like to let you know that your feedback has been forwarded to the proper department. Your comments are important to us and help with the development of our online video streaming community.

      Reply
  3. Kate

    I am already a paid member….why is your site trying to charge me for some very basic lessons that I could get on u-tube for free….For my membership fee I expect to get some adult sewing education, not a bunch of small projects where I make useless clutch bags and the like or some tips that a child would already know. Your project lessons only have show two skirts, one that is just a balloon and another that is so basic that it is not even worth watching….You have hardly anything on pattern making even for videos that you are trying to squeeze money from your patrons….This is not what you call good branding for your business….I do not want to pay anymore money and I want to get more adult sewing education for what I have paid…..Get your act together and give me some PREMIUM sewing instructions since that is what I expected when I gave you my money…..Kate

    Reply
    • National Sewing Circle

      Hi Kate. Thank you for taking the time to let us know how we can serve you better as a customer. We hear you and are working to develop and provide content that will fit your needs as well as content that will fit the needs of up and coming sewing enthusiasts who are looking to develop their skills. We would like to give you free access to the class: Alter and Sew A Custom Dress Shirt.

      Reply
      • Mary

        I have to agree with Kate (Jan 9th)…I too wonder when we shall have some new ideas. YouTube has everything you have, and it’s free!

        Reply
        • National Sewing Circle

          Hi Mary. Thank you for your feedback. We do appreciate your comments. I will forward this on to the proper department.

          Reply
  4. Patricia

    I would love to see a video that teaches how to measure for and do a variety of button holes for the different button shapes. I would like to know how to mend buttonholes that come undone as well. I would like to see the applications of by hand and on the sewing machine (manual and automatic) Thanks

    Reply
    • National Sewing Circle

      Hi Patricia. Thank you for your feedback. Your suggestion has been forwarded to the proper department.

      Reply
  5. Carolyn

    Thank you for the fitting tips. I don’t like having to fit with a muslin, but it sure pays off in the end. I have a question. How would one go about a FBA on a pattern for a tunic/cardigan with kimono sleeves designed for moderate stretch knits.

    Reply
  6. Sandra Collin

    I keep getting messages to pay $9. for the premium upgrade and I paid for this but keep getting the e-mails and cannot bring up the video’s???

    Reply
      • Elizabeth

        Can you send me the same link? I keep being asked to pay for my membership and it is annoying.

        Reply
        • Customer Service

          Hi, Elizabeth. We are sorry to hear you are having trouble viewing the video. Please contact us at 1-855-208-7187 so we may assist you.

          Reply
  7. Hester

    I have a hard time with patterns because I don’t fit in them. I am one size for my bust and a whole lot different for my waist and even worse for my hips. So to make something I have to buy patterns with a wide range of sizes. It drives me crazy. When I was young I could just buy a pattern and select the size and sew it. Now it has become so complicated.

    Reply
    • Elise

      I agree with Kate I expected more, particularly as your sit came recommended by McCall patterns. It is very annoying that firstly i understood the service was free, then I was offered the site fur $39 approx with a discount and ended up paying $7, what happened to FREE. Now that I’m on the site there is some videos which are useful but now you want more money gut a premium service. Come on, if you want to maintain a strong and growing customer base who are loyal then show some quality and loyalty to your customers otherwise I will cancel, or report your site to consumer affairs 😏

      Reply
  8. Laurie

    Interesting comments, I don’t recommend trying to alter clothing or muslins on yourself. After years of customer alterations, I know that when you look down, your movement is enough to change the way things fit when you stand up straight. Get a friend to help, then they can check to be sure things look right. I buy old sheets at the thrift store, and I am often given sheets to use for muslins. The duct tape dress forms are great. And so far I haven’t seen much in the videos to make me want to purchase a membership.

    Reply
  9. Rosetta Peters

    I would know how to alter a regular to fit a lady with large breast.

    Reply
  10. Betty White

    I loved your expertise on the muslin. I’ve not seen in a few years but plan on starting back. I enjoyed your lesson and will definitely try the muslin pattern as I have lost weight and will try it first. Thanks so much for the lesson.

    Reply
  11. Liliana Chang

    I like sewing but my size is harder because my weis es biges and my hips alson but if I go to the other size is to big do I need help.

    Reply
  12. 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.

    Reply
    • Peggy

      Lindaflor, the inseam for pants is measured from the center of the crotch down to the length you want at your ankle, crop, capree or lower. If you have a pair of pants that has the inseam length you already like, you can measure from the center of the crotch to the hem and use that measurement. The back rise is from the center of the crotch to your back waist, lower waist or top of hip, depending on where you like your pants to sit. Measure from the center crotch to the front waist, high, low or inbetween and then use that measurement. Remember to add seam allowances. It’s also best to have a friend do the measuring to make sure the numbers are really accurate, unless you use a pair of pants you have already.

      Reply
  13. 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.

    Reply
  14. Jonalyn

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

    Reply
    • Customer Service

      Hello Maryna,

      We are glad that you are interested in joining our membership. Here is a link to sign up for the membership for a promotional offer of $2.99 for your first year of membership. https://go.nationalsewingcircle.com/C13777

      Thanks,

      Becky
      National Sewing Circle Video Membership

      Reply