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Fitting a Full Bust | Video

Learn why patterns don't fit straight out of the envelope, and how to adjust the bust for a smoother, more flattering fit.

Video: Cari Delahanty, Jeff Roos, Carol Fresia

Full-busted women often have trouble finding a good fit in ready-to-wear garments, and it’s not much easier when working with commercial patterns. Daryl Lancaster, a frequent Threads contributor and sewing instructor, explains how to determine the pattern size you need for your body structure. Then she explains how to add or increase a bust dart to improve the fit.

Find your pattern size

Daryl suggests working with the chest size, rather than the full-bust measurement, to determine which pattern size to sew. Take the chest measurement around the body, above the bust and under the arms. Then measure the full bust. There’s an easy formula for using these dimensions to calculate the pattern size you need.

You’ll also learn how commercial pattern sizes were developed in the decades following World War II, and why they don’t fit most women straight from the envelope.

Add or increase a bust dart

Patterns are drafted for a figure with a bust circumference 2 inches larger than the chest circumference. If your measurements have a larger difference, you need to add a dart (if the pattern doesn’t include one) or increase an existing bust dart. Daryl takes you through this process step by step, noting that a similar adjustment can be used to reduce the bust cup for A-cup figures.

Once you’ve added or enlarged the dart, you redraw the dart and lengthen the hem at center front. For figures with a full bust but slender midriff, some of the added width below the bust can be taken out with a vertical dart. Again, place the dart point 1 inch to 1 1/2 inches directly below the bust point.

Insiders can learn more expert techniques from more Daryl videos, including “Tips for Cutting Bias Strips” and “Pro Techniques for Applying Bias Binding.”

Previous: Add a Bust Dart to a Sewing Pattern Next: Add Room with a Simple Bust Adjustment


  1. Deleted | | #1


  2. User avater
    sue1143 | | #2

    Thank you for such a complete presentation of this- MY! - sewing issue. Daryl is an amazing teacher

  3. user-7028407 | | #3

    Enjoyed this! Very clear and helpful!

  4. jinglefishart | | #4

    Great information and clear presentation. Well done. Thanks!

  5. tinainanderson | | #5

    Where can I get a copy of those 2 charts Daryl uses in the video?

  6. copp2023 | | #6

    When doing the FBA on pattern without a dart, how deep should the dart be?

    1. Marsha428 | | #7

      Having wrestled with this issue my entire sewing career, I would say the dart needs to be as deep as it is once the FBA is done. However, this can create a HUGE dart, particularly in woven fabric which can necessitate a different way of handling the construction. I've learned how to manipulate some of the fullness to other areas. In knits, like a tee shirt the fullness can be eased into the side seam if you don't want a dart. I hope this helps you.

  7. User avater
    [email protected] | | #8

    Wow, thank you Ms. Lancaster for this outstanding instruction for adjusting for a cup adjustment and reworking the dart! This is the best illustration and demonstration I've seen for this topic. I hope I can still find this once I (hopefully) regain the weight (and "assets" measurement) I lost over the past 6 months due to a health issue. This will even help me resize "smaller" in the meantime until that weight comes back!

  8. biljanab | | #9

    How did you determine how much you have to spread those two pieces? For D cup, you spread them 3/4" apart, but how did you calculate that value?

    1. carolfresia | | #10

      There's a formula for how much to spread the pieces, but I would say to start with 3/4 inch and see how that works for you in a muslin test garment. You may want more or less. This can depend on the garment style and its overall amount of ease, plus your general shape and bust projection. All D-cup bust shapes aren't the same.
      Carol Fresia, Editor, Threads magazine

      1. biljanab | | #11

        Thank you Carol. Would you mind sharing the formula so we can have something to work with when dealing with other cup sizes? For example, my sister's cup size is larger than D, so I would like to calculate the adjustment necessary to start with.

        1. carolfresia | | #12

          Here's a link to a post that has a table with the standard amounts to add for a full-bust adjustment.
          I recommend starting with the amount given in the table and making a test garment (even half a front would give you something for your sister to try on). Depending on the pattern and the wearer's shape you may want to increase or decrease the amount of the adjustment.

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