How to Fix a Gaping Armhole

Is your armhole gaping open and showing your bra? Learn how to do a gaping armhole adjustment with this simple pattern fix.

If you’re curvy, gaping armholes that flash your bra are an all-too-common problem! The good news is they’re easy to fix once you know what’s causing them.

Before you dive into this adjustment, figure out the root cause first. Gaping armscyes can have a few different causes:

• If the gaping is fixed by pinching the outer shoulder seam, you need a sloping shoulder adjustment instead
• If the armhole is gaping because it’s being pulled forward by your bust, you need a Full Bust Adjustment instead
• If neither of those is the issue, then this gaping armhole adjustment is the one for you.

How to Tell If You Need a Gaping Armhole Adjustment

• The armhole has excess fabric that’s creating gaping or folds
• The issue isn’t solved by pinching the shoulder or doing an FBA

Measuring How Much to Adjust By

On your muslin, pinch a dart out of the excess fabric so the armhole lies flat against your body, and pin it in place. Mark the dart on the muslin, then unpin and measure the distance between the dart legs—that’s how much you need to remove. Also note how far the dart is from the bottom of the armhole.

On a Darted Garment

Step 1: On the front pattern piece, draw a line through the center of the bust dart all the way to the bust apex. Then draw a second line from the bust apex to the point on the armhole where you marked the center of your pinched dart. Now draw a dart at the armhole with the legs the distance apart that you measured, ending at the bust apex.

Step 2: Cut out the armhole dart completely. Cut along the line through the bust dart, leaving a small hinge at the bust apex. Swing the piece above the bust dart up and to the right to close the armhole dart.

Step 3: Trace your new pattern piece, drawing in the bust dart using the original dart legs. True the dart extension (make sure both legs are the same length). As you trace the new armscye you may have to slice off a little on the upper part and add a little to the lower part to get a smooth line – make sure to use a curved ruler like a French curve.

On a Dartless Garment

There’s a slightly easier way for dartless garments that are knit or only need a small adjustment. If your dartless garment needs a bigger adjustment, use the technique above, creating a new bust dart in the process.

Step 1: Draw the dart from your muslin onto your front pattern piece, in the same position where you pinned it.

Step 2: Fold the dart closed by creasing down the center and bringing the two dart legs together.

Step 3: Flatten the pattern piece as best you can and tape the dart closed.

The paper won’t lie perfectly flat—and that’s absolutely fine! This technique works beautifully for most knit fabrics and for small adjustments on wovens.

You Did It!

No more flashing your bra every time you lift your arm! Your armholes will now sit smoothly against your body.

Want to dive deeper into fitting? This adjustment and many more are covered in detail in Ahead of the Curve, our best-selling book on fitting for curves. And if you’d like in-depth video tutorials that go much deeper, check out Cashmerette Club‘s library of fitting masterclasses.