Full Bust Adjustment
Your pattern pulls across the bust or the side darts don't lie flat? You probably need a Full Bust Adjustment. Enter your high bust and full bust measurements — we'll calculate the exact slash-and-spread amount for your pattern type.
How the princess seam FBA works
Princess seam patterns have no bust darts — instead, the front is split into a center front panel and a side front panel joined by a curved seam that passes through the bust apex. This seam does the work of shaping; a larger bust needs more width and curve at that seam.
The princess FBA uses the same adjustment amount as a darted FBA but applies it differently: the side front is slashed and spread to add width, and the center front curve is deepened to match. Both changes are centered at the bust point.
How to take these measurements
High Bust
Wrap the tape directly under your armpits, above the bust. Keep it parallel to the floor, snug but not tight. This sets your pattern size.
Full Bust
Wrap the tape at the fullest part of your bust, parallel to the floor. Wear a well-fitting, non-padded bra. Don't compress — the tape should rest against your body. This sets your adjustment amount.
Related tools
Pattern pulls across the bust? Calculate the exact slash-and-spread amount for darted bodices.
Overlap the side front and flatten the CF curve for smaller busts on princess-seam patterns.
Is your pattern too tight or too loose? Compare your body to the pattern to check ease by fit style.
Enter bust, waist, and hip — find your size across 11 brands with size charts. Sewing sizes ≠ store sizes.