Doing a Full Bust Adjustment (FBA)

Have you ever heard of an FBA? But you don’t know what it is and what it’s used for? Then I’ll explain it to you right here!

So an FBA, or Full Bust Adjustment is a modification you can do to a front bodice, where there isn’t enough room for the bust.

If you have a relatively large bust compared to your other body measurements, it can be a good idea to adjust for this to get a better fit. There is no (as far as I know) bulletproof way of telling whether a woman has a relatively large bust, but if you often find that your blouses and shirts ride up the stomach or the button placket is stretched to the limits, it’s usually a pretty telling sign!

Many beginner sewists think that you can add more room to the bust by simply grading a size up. WRONG! This won’t solve the issue of missing vertical length from the high shoulder point to the waistline, which is causing the garment to ride up the torso.

Most sewing patterns are constructed the same way as ready-to-wear (RTW) clothes meaning that sewing patterns are also drafted for women with a cup size around EU B-D no matter the size. Some sewing pattern companies offer different cup size options (especially in the larger size ranges) which is a great alternative.

If you buy a sewing pattern from Beklaedt, sizes EU 34-46 are drafted for a woman using a cup size of approximately A-D.

For sizes EU 48 up to 60 the assumption is that the cup size increases gradually with the size meaning that EU 48-54 fits approximately a cup size of E-H and sizes EU 56-60 fits cup sizes I-K.

However, many women need to make personal adjustments regardless their size. Luckily, it is fairly easy to adjust a sewing pattern for a fuller bust!

To do an FBA you basically go through the same steps as you would to add a bust dart to a dart-less front bodice (see my other article reference!):

Step 1:

Find the front bodice piece

Step 2:

Draw a vertical line starting at about the centre of the waistline up until the apex point. Then draw a line from the apex point to the lower third of the armhole.

Step 3:

Slash the front bodice into 3 separate pieces, 1a, 2a and 3a. However 1a and 3a should be connected by the armhole and 3a and 2a should be connected by the apex point. Move 3a away from 1a which in turn shifts 2a downwards. By doing so we create a bigger side bust dart.

Step 4:

Make sure to extend the vertical length of 1a from step 3 so it matches the new (lower) waistline created by the vertical shift of 2a. Add an optional waist dart if you want to maintain the original waist measurement. Make sure to shorten the dart a little so it doesn't directly on top of the apex point.

Conclusion:

So, the big question is how “big” should the FBA be? Well, that depends on your individual body measurements. A good starting point would be to consult body measurement number 4 in the general size guide and compare it with your own measurement. Then you can try increasing the depth of the dart by a couple of cm’s (1 inch) first and see how it transforms the fit…