How to make bust adjustments on your sewing patterns

Struggle to get patterns to fit your bust? Try doing a small or a full bust adjustment to get a better fit.

As most commercial patterns are cut to fit an American B cup, you may need to make a full bust adjustment if you are bigger or smaller.

Whilst it can seem a little daunting to anyone new to pattern adjustments, this really can make a massive difference to how your clothes fit.

If you have a small frame, with a full bust, and you use your bust measurement to select a pattern size, the chances are that the clothes won’t fit around your neck, chest and armhole.

If you’re smaller busted, you may have unsightly excess fabric folding around the bust.

NB- The full and small bust technique was developed and originally published in  Fit For Real People by Pati Palmer and Marta Alto

bust adjustments

If your full bust measurement is bigger than your high bust by more than 2.5” (6.5cm) you’ll need to do a full bust adjustment (FBA). In this case, use your high bust measurement as your base pattern size.

If your full bust measurement is 1”(2.5cm) or less than your high bust, then you’ll need to do a small bust adjustment (SBA). Use your full bust measurement as your pattern size in this case

There’s no exact science to measure how much of a bust adjustment you’ll need. It also depends on whether you’re making a loose-fitting garment.

First of all you need to work out how much additional space you require around the bust or what you’d like to remove. Below is a helpful chart to work out the amount.

The process of adapting the pattern for both types of adjustments are the same except that for an FBA, you will spread the pattern to add space and for an SBA you will reduce space by overlapping the pattern.

Bust adjustment examples


  • Lay the tissue pattern against yourself to establish where your bust point is. Mark onto the pattern with a cross.
  • Using a ruler and pencil, draw a vertical line from the marked point to the hem. Make sure the line is parallel to the grain line on the pattern.
  • From this line, draw a second line up towards the armhole, hitting the lower third of the armhole. Together these two lines are called line 1.
  • Draw a second line horizontally through the middle of the bust dart, meeting line 1 at the bust point. Label this line 2.
  • Draw a third line horizontal line a little above the hem between line 1 and the centre front of the pattern. Label this line 3.
Marking a pattern for a bust adjustment
Image based on original artwork from Fit For Real People by Pati Palmer and Marta Alto
spreading a pattern to create a full bust adjustement
Image based on original artwork from Fit For Real People by Pati Palmer and Marta Alto
  • Cut along line 1 from the hem to the armhole, making sure you don’t cut all the way through the armhole. Leave a hinge so you can pivot the paper. The point of the dart has now swung away from its original position.
  • Cut through the line in the middle of the dart,again leave a little hinge at the tip of the dart so you can pivot.
  • Line up the cut edges of line 1 so they’ve been spread apart by the amount of your FBA. The edges should be parallel to one another. You’ll notice that your dart has now spread apart too and become bigger.
  • The lower edge of your hem no longer meets at the bottom, as the side that has been adjusted and is now longer. Cut the third line you drew, and spread apart until your hem is level.
  • Fill spaces with tracing paper, and stick in place.

spreading and filling in a pattern for an FBA

Image based on original artwork from Fit For Real People by Pati Palmer and Marta Alto


Draw in the lines as per an FBA adjustment. Cut the lines as previously instructed. Now we essentially perform the same process in reverse. 

Swing the darted side of the pattern across the other side, by the desired SBA amount. Your waist and bust darts will both be reduced.  The lower edge of the hem no longer meets at the bottom, as the side that has been adjusted is now shorter.

Cut the third line you drew, and overlap until your hem is level. Re-blend the lines around your adjusted bust dart.

Small bust adjustments
Image based on original artwork from Fit For Real People by Pati Palmer and Marta Alto
CL's top tip


Compare the front and back bodice pieces along the underarm seam – folding the bust dart out of the way – to ensure your bodice will be the same length the whole way around!

If you’d like to learn more about different bust fitting techniques buy Fit For Real People by Pati Palmer and Marta Alto or the excellent DVD by the same team


  • Gemma Hunter

    07.08.2017 at 13:42

    This is so straightforward thanks. Couple of quick questions: When drawing the line up to the armhole, does it matter if it is the bottom 1/3 or the top 1/3? I’m finding that when I do the bottom 1/3 it distorts the armhole shape?
    Also if you don’t have a side dart (like on a T-Shirt) do you just draw the line straight to the side seam?

  • Suz

    17.04.2017 at 02:28

    Very easy to understand. Thank you

  • Hélène Martin

    17.08.2016 at 10:08

    Thank you for also including the SBA with a great illustration! I don’t think I’ve ever seen instructions beyond “do the opposite of an FBA” and I had a really hard time with that as a beginner.

  • Ann Warner

    14.08.2016 at 17:18

    Thank you, this has been so well explained that I’m actually going to try it for the first time, Ann

    • The Thrifty Stitcher

      15.08.2016 at 10:57

      Thanks for your comment Ann, Glad you’re now going to have a try! If you make a mistake you can always stick the bits back together again, so nothing to lose really!
      happy Bust adjusting
      CL :)

  • Arlene Kelaart

    14.08.2016 at 16:42

    Brillient such clear instructions…can’t wait to try it. My adjustment will be a FBA.

    • The Thrifty Stitcher

      15.08.2016 at 10:59

      Hi Arlene,

      Thanks for your kind words, glad you liked the instructions. Good luck with your first FBA!

      happy stitching
      CL :)

  • WheelyBad

    14.08.2016 at 12:48

    A really clear explanation, this will be a really handy reference to remind me what to do. Thank you :-)

    • The Thrifty Stitcher

      15.08.2016 at 11:00


      Thanks for taking time to read the post and comment really pleased you liked the post. Good luck with any future pattern alterations

      Best wishes
      CL :)