How to add a Side Dart for Proper Fit

How to add a side dart

Part of the beauty of sewing for yourself is the ability to make every outfit fit perfectly to your body. But of course, not all patterns are created equal, and sometimes it can be quite tricky finding the perfect fit for all of our different curves. Justine of the Sewing Rabbit Team is here today showing you how to add a side dart into any shirt pattern, to help make your new top fit perfectly to your shape. You will be amazed at what sewing one tiny little dart can do for proper fit.

How to add a Side Dart


Hello Me Sew Crazy readers! Justine here with a fitting tutorial for you today! A common problem many women have when sewing tops for themselves is a gaping armhole. Most sewing patterns are drafted for a size B bra cup size so If you are bigger then that, then most likely you have encountered this problem. But how do you fix it, especially if you are sewing from a pattern that doesn’t have any darts? You have to create your own dart. And today I’ll show you how !

But first, I’d like to talk a little to you about the importance of sewing a muslin mock up. While making a muslin isn’t that necessary for sewing for children with their straight up and down bodies, getting used to making a quick one for yourself will save you many headaches and wasted fabric in the future. Believe me, you don’t want to cut into a piece of forty dollar a yard fabric until you have made a muslin. And many fitting issues require making one, including fixing the armhole gap. Muslins only take a few minutes, and only need to be basted together quickly.
A gaping armhole occurs when your bust pulls the armhole forward. The only way to solve this problem is by adding a dart, which makes your armhole smaller. You COULD just sew a dart into your fashion fabric and be done with it, and make no muslin at all, but armhole darts don’t look very nice and scream HOMEMADE. A better alternative is to transfer the dart to the side seam of the top. And you have to do the work on the muslin, then change the pattern.finishedtopresizedHere is my finished top I made of silk with leather sleeves, with the side dart sewn into it. It’s fitted to a DD cup size , yet is nicely fitted with no gaping.

FIXING THE GAP: pinnedmuslinresized Sew a muslin of the bodice of the top. Try it on yourself or a dress from that is padded to fit you. You can have someone help you pin it to you. In the case of this pattern, it’s meant to be a pullover top and didn’t need to be pinned. Pin out the excess fabric in the armhole. Trace the dart with a pencil. Make sure to mark the apex, or bust point, while the muslin is on your body or form.gapintute1 Take the muslin and lay it on the sewing pattern. Use transfer paper to trace the dart and the apex to the pattern. Get used to marking your apex .Most fashion designing hinges on it.gapingtute3Draw a line through the center of the dart to the apex. Draw another line about 3.5 inches below the armhole on the side seam and connect it to the apex as well.gapingtute5Cut through both lines almost to the apex, but not cutting through it. Pivot the armhole dart closed. Voila! The side seam line will open up, creating a new dart. This technique is known as the DART PIVOT METHOD.gapingtute6Patch behind the armhole and side seam dart with scrap paper. Draw a new armhole with a French curve ruler if you have one. A French curve ruler is a great tool for drafting armholes, and every dressmaker should have one. Close the side seam dart and cut on the seam allowance.gapingtute7You will need to redraw the dart about 1.5 inches from the apex. You do NOT want your dart ending at the apex. Trust me. The bigger you are the farther away from the apex the dart should end , BTW 1 inch is normal for a B cup. I’d go up about 3/8 inch for each size.

How to Add a Side Dart to fix your Shirt Pattern Fit.  #sewing

Thanks so much for stopping by, and until next time…

Happy sewing!

Justine Abbitt

Contributor at Sewing Rabbit Team
Author of Sew Country Chick, Justine loves to update her 100 year old farmhouse in couture style. She currently resides in California with her husband and three children.

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  1. Red Fox says

    I have been trying to solve this problem for aaaaaages! One question that always stumps me – doesn’t this shorten the armhole? If it does – do I need to shorten my sleeve cap, or should I lengthen the back armhole, or what? Seems counter-intuitive to me that larger bust = smaller arms.

    • says

      I have the same question as Red Fox. It seems like this is going to make the arm hole a lot smaller. About 3 inches in this case.

      It does look lovely, though and it simpler than a full bust adjustment unless it means that you also have to adjust the sleeve cap.

    • says

      Yes, you do remove some fabric from your armhole and you may need to remove some length from your front arm pattern. Most commercial sleeves have too much ease anyway, and I would measure the sleeve and adjust. That’s why you can get a slight gather on patterns that aren’t supposed to have sleeve gathers. TOO much ease! But make sure you make the armhole at least 1 3/8 larger then the total armhole measurement. If the sleeve is the same as armhole the fit will be too tight at the cap

  2. Sorahart says

    Really interesting material, thanks for sharing! I usually have to cut a bigger size to fit my larger frame but it is always massive for my small bust. I’ve been trying to figure out how to make adjustments for a long time and you gave me lots of ideas of where to start.

  3. says

    Wow, this is one of the better tutorials on how to eliminate the gaping without major re-work. Other tutorials have all sorts of crazy maneuvers. Once the fullness is redistributed as a side seam bust dart you should drop the armhole to maintain the total circumference without worries of gaping- unless of course you want a smaller armhole.

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