Bust Dart Adjustment: How to shorten or lengthen a dart

Jess is here today to show you how to adjust the length of a bust dart if it’s too long or too short. When we put together a (pretty comprehensive, I might add) list of common pattern adjustment tutorials for the Beatrixalong Muslin post (day 2), we couldn’t find one showing how to lengthen or shorten a dart. Whaaat. Anyway, Jess has had to do this adjustment on her Beatrixes, so she took a few pics to show you just how easy it is. Here’s Jess:

This is the easiest bust dart adjustment EVER! In these photos, I’m wearing my Beatrix muslin with dots representing where the dart ended before the adjustment (closer to the middle) and after the adjustment (closer to the sides).

With the darts sewn as they were in the pattern, they ended pretty much exactly on the bust apex.

dart shorten

The darts are at a good height, and the size is right, though, so the only thing I wanted to do was shorten the dart by an inch. Generally, you want the dart to point in the direction of your bust apex, but ending 1/2″ – 1″ short of the apex. (Rae adds: typically the 1″ is for bigger busts, 1/2″ for smaller busts)

dart adjustment

Here’s the Front Bodice pattern piece from Beatrix, traced in my size. All I had to do was make a new point on the dart’s center line one inch away from the original point, then re-draw the dart legs using a straight edge, and starting at the same points on the side so they’re the same length and they don’t change the side seam.

dart shorten

If you need to lengthen the dart, simply extend the center line by the amount you need, and re-draw the dart legs exactly the same way.

dart shorten


See how easy? For additional pattern modifications, be sure to check out our awesome list of links in this post. You can find all of the Beatrixalong posts by clicking here.

3 thoughts on “Bust Dart Adjustment: How to shorten or lengthen a dart

    • Man, where was this post one week ago when I was modifying the darts on my first washi??? This is a lot simpler than the way I did it. Thanks for sharing.

  1. I’m wondering if you can help me-I am trying to shorten the bust darts on a velveteen dress-regrettably the person who made the mistake CUT what she saw as excess fabric so when I unpicked the dart she’s made I had a bit of a shock.How can I fix it? i thought of sewing in insets to replace the missing fabric?…Help!!! Thank you 🙂

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