Hello, hello!

First I want to thank you for your comments on my Flora Dress. It’s really nice to have this positive feedback when you worked so hard on a dress!
I promised to write a tutorial on the low bust adjustment (LBA) I did (over on a monthly stitch, some people asked about it) and here it is! The principle for an LBA is the same as for a high bust, so I briefly go over that as well.

So let’s start with the most important thing first: when do you need a low/high bust adjustment (LBA)?
You’ll need an LBA if the fullest part of your bust is lower than where it’s supposed to be, comparing to the pattern you are working with.
You’ll need a high bust adjustment (HBA) if the fullest part of your bust is higher than were it’s supposed to be comparing to the  pattern you are working with.
This is a bit abstract, but it will become more clear when you follow this tutorial!

What do you need

  • Front bodice pattern piece of the pattern you’re working with
  • ruler
  • measuring tape
  • pencil or pen
  • tape
  • extra piece of paper
  • tracing paper (optional)

Step 1
Take a measuring tape and measure from your shoulder to the fullest part of you bust.01 apexHere’s my dressform with a measuretape pinned to her, to clarify this a little bit.
Now, write this measurement down on a piece of paper so you don’t have to do this again!

Before you go any further, you might want to trace the pattern piece. I always do so, ’cause I sometimes mess up my adjustments and if I’ve trace the piece, I still have the original piece to start over.

Step 2
Next, take the front bodice pattern piece.
Check if it includes seam allowances. If it does, you need to draw the seam allowance line on the pattern piece at the shoulder seam. If it doesn’t you are good to go!
Now, we need to find the apex on our pattern piece. To do this, draw a line through the middel of the bust dart and the waist dart. (Blue lines on my drawing)
The intersection point is the pattern apex. (red dot)
1 apexNow, measure from the shoulder line (without seam allowance) to the apex and write this measurement down as well!
Compare the two measurements, if they are the same, you are good to go. If one of them is bigger than the other one, you might need adjustments.
If your shoulder-apex length is more than the pattern’s length, you need an LBA.
If your shoulder-apex length is less than the pattern’s length, you need an HBA, which is basically the same but the other way around. You’ll decrease the amount of space between shoulder and apex on the pattern piece.

My shoulder to apex length is 27, on my pattern piece it is 24, I need a 3 cm LBA.

Step 3
Take a pen and draw a horizontal line, right-angled to the center front of your pattern piece. Draw one above the bust dart (green on my drawing) and one below the bust dart (orange on my drawing) It doesn’t really matter how high or low you draw this lines, as long as the bust dart is in between the lines and they are right-angled to the center front.
2 draw lines
Step 4
Now we’ll adjust the pattern.
If you have a low bust, go ahead and cut the pattern at the upper line (green) above the dart.
Tape the top piece one sheet of paper. Tape the low piece also on the paper, but leave a gap that measures exactly the difference between your measurement and the pattern’s measurement (in my case, it’s the 3 cm.)
Make sure you keep the center front straight!
If you have a high bust, fold the upper line (green) up with the amount you need to subtract from the pattern.  Tape it down, but make sure you keep the center front straight!
This picture shows you how to cut up and tape down the pieces.
3 add needed length
Step 5
Straight your sideseam out. It’s the light blue line on my pattern piece.
Do this by connection the corner made with the armscye with the corner at the waist. Cut excess paper of. Make sure you keep the center front straight!
4 adjust side seamStep 6
Now we need to remove the length we added above the dart if we did an LBA. To do this, fold away the same amount of paper as you added, starting from the line below the bust dart (orange line). Tape it down. Make sure you keep the center front straight!

If you did an HBA, you need to add the length you folded out at the green line. Do this by cutting through the line below the bust dart (orange) and adding it here again. Use the technique described in step 4 for an LBA. Make sure to keep the center front straight!
5 fold lowest line down

Step 8
Adjust the side seam again as shown in step 6.

Step 9
You only need to add this step if you folded your fabric into the waist dart. Otherwise, you are done!
If you folded into the waist dart, the top of the dart, the pointy part, is now gone. You need to fix this again. Measure down from the apex on the pattern piece, this should be the same length as the original length between apex and dart point. Mark this with a new point.
Draw new dart legs by connecting the dart points on the waistline with the new drawn dart point.
6 adjust waist dartOn the right is the original pattern piece, on the left is my redrawn dart.

Your pattern piece looks something like this now:
7 adjust side seam again doneCongratulations! You are done.
I always encourage to make a muslin, since you might need to try if the fit is right now.
Sometimes, when I do this adjustment, I still need an FBA, but not always. It depends on the drafting of the pattern and the amount of ease in the pattern.

I hope you have found this tutorial helpful!
If you still have any questions, please ask! If you have any tips, please post them in the comments as well.
Happy sewing!

  • Great tutorial, Thank you! This has made it very clear. ( and as the years go by, I think that LBAs are going to become more and more necessary!)

    • Thanks! Your comment made me grin. I think so too about the “more necessary” part!

  • Emily – Belgian Seams

    This is so amazing, Hanne! I think this could be the reason for a lot of my ‘it’s ok but not quite right’ fitting problems! Thanks so much for the post!

    Can’t wait to talk about LBAs, HBAs, SBAs and FBAs on Saturday! #sewinggeeks

    • #sewinggeeks for the win! Good luck with it!

  • ah, super! sinds de borstvoeding nog geen nieuw stuk genaaid maar dit ga ik nu dus zeker nodig hebben :-). Heel duidelijk uitgelegd, fijn!

    • Fijn dat het duidelijk was! Succes ermee!

  • This is very usefull information. I should check it out on the next project I make