Full bust adjustment (FBA) basics
An FBA adds room over the bust without making the shoulders and neckline bigger. You slash the front pattern piece and spread it to add width and length at the bust.
Pinny's tip
Choose the size by high bust (measured above the bust under the arms) and use an FBA if your full bust is more than about 5cm larger.
Choose the size by high bust (measured above the bust under the arms) and use an FBA if your full bust is more than about 5cm larger.
What you'll need
- Front pattern piece, traced: keep the original.
- Paper and tape: to fill the spread.
- Ruler and pencil: for the slash lines.
Step by step
- Mark the bust point on the front piece.
- Draw a line from the hem up to the bust point, then on to the armhole.
- Draw a second line from the side seam to the bust point (through the dart if there is one).
- Cut along the lines, leaving tiny hinges, and spread to add half your extra bust amount at the bust point.
- Tape paper behind, redraw smooth lines and true the side seam.
- Check with a toile.
Watch
How to Do a Full Bust Adjustment on a Dartless Bodice | Beginner-Friendly Sewing Tutorial (3:38)
By Tilly and the Buttons · Open on YouTube
The video this technique page has always pointed to, a 3-minute one from Tilly and the Buttons. Embedded from YouTube with credit; we don't host it. It only loads when you press play.
Common mistakes
- Adding the full amount on one piece. The front piece is half the front: add half.
- Not redrawing darts. A new or bigger dart is usually needed on darted bodices.
- Skipping the toile. Check before cutting.
Watch it done
- How to Do a Full Bust Adjustment on a Dartless Bodice | Beginner-Friendly Sewing Tutorial by Tilly and the Buttons on YouTube. Opens on YouTube; the video belongs to its creator.
- The Simple Way To Adjust The Bust (Full Bust Adjustment) On Any Sewing Pattern! by Sew Anastasia on YouTube. Opens on YouTube; the video belongs to its creator.
- How to do a Full Bust Adjustment- Pattern Drafting for Beginners by The Creative Couture Studio on YouTube. Opens on YouTube; the video belongs to its creator.
Sources
All checked 1 November 2026. We read these; we did not test the products ourselves.
- Tilly and the Buttons: How to Do a Bust Adjustment on a Darted Bodice (FBA & SBA)
- The Sewing Directory: Making a Bust Adjustment to a Pattern
- YouTube: How to Do a Full Bust Adjustment on a Dartless Bodice | Beginner-Friendly Sewing Tutorial (Tilly and the Buttons)
- YouTube: The Simple Way To Adjust The Bust (Full Bust Adjustment) On Any Sewing Pattern! (Sew Anastasia)
- YouTube: How to do a Full Bust Adjustment- Pattern Drafting for Beginners (The Creative Couture Studio)