In terms of pattern making, a full bust adjustment (FBA) is modifying a garment to fit a fuller bust by adding width and length to the bust area without altering the fit of the shoulders, neckline, back, or waist. Instead of simply “scaling” the entire pattern, you surgically add the space your body actually needs and keep the rest of the garment proportional and stylish.
Most commercial patterns are designed for B-cup blocks. That said, if you’re someone with a larger bust, you’ll often see draglines, flared armholes, pulled front openings, or hems that rise up the front.
Learn how to pattern full chest adjustments
Torso sloper with front seam darts and back neck darts for full bust adjustment. (Image source: University of Fashion)
Full Breast Adjustment Lessons from the University of Fashion
Full Chest Adjustment classes are taught by Martha Palaza, a fit expert who has conducted fit workshops throughout the Boston area. In her UoF class, Martha demonstrates how to change torso slope for a bust cup larger than B based on ASTM standard D8555-11 anthropometric measurements for adult microscopic size (sizes 00-20). She also demonstrates how to progress from a C to a D to a DDD cup. 
Martha’s Breast Cup Calculation and Cup Size Range Charts accompany this lesson and provide key calculations and guidance. (Image source: University of Fashion)
How to increase your FBA bust size using Fabulous Fit’s fitting system and pads. (Image source: University of Fashion)
In class, Martha uses pads from the Fabulous Fit Fitting System to increase her breasts from a B cup to a C cup and from a D cup to a DDD cup. If you don’t have a Fabulous Fit Fitting System, get creative and make your own using round shoulder pads or polyfill.
Extract key measurements from the dress form for FBA: Chest Circumference, Under Chest Circumference, High Point Shoulder to Peak, Chest Width (peak to peak). (Image source: University of Fashion)
Split the front sloper in preparation for increasing the bust cup from a B cup to a C cup. (Image source: University of Fashion)
After recording your measurements in the Chest Cup Calculation and Cup Size Range Chart, you will learn how to use the Cup Size Range Chart to demarcate the essential areas of your front sloper in preparation for increasing the chest and length areas of your sloper.
Test a full chest adjustment fitting made of muslin or test cloth. (Image source: University of Fashion)
Once the chest cup adjustment slopers have been created, make a test muslin to check the following: Make sure 1) there is enough room at the side seam/armhole intersection, 2) there are no drag lines in the side seams, 3) the darts disappear at the peak, 4) the waist darts are aligned with the princess line, and 5) the waist sits at the waist line and does not ride up.
Shift your mindset: From “fixing the flaws” to designing for reality
Learning full chest rowing patterns isn’t just about “fixing your chest.” Learn how to draft on the real body, regain your comfort and confidence, and step into the realm of true fit engineers as a designer and maker. At a deeper level, learning FBA patterns is an act of inclusion. The report acknowledges that “standard” breast ratios exclude a significant proportion of women and people with feminine figures, especially plus-size and curvy seamstresses.
By training FBA normal By adjusting patterns rather than “special problems,” we shift the narrative. There is nothing wrong with your body. The pattern has incomplete measurements so it fits across the shoulders and upper chest and adds chest volume that the pattern did not account for. Join Martha to find out how.
