August 31, 2020

Today on the blog I am going to show you one of my most frequently requested tutorials – how to add a dart to a dartless Ogden (sizes 0-18). It is a simple process and I am excited to show you step by step how to achieve this for your self.

The 0-18 size range of the Ogden is drafted for a sewing size C cup. This is not the the same as a ready to wear size. In sewing, a 3 inch difference between your upper and full bust equals a C cup. A 4 inch difference is referred to as a sewing D cup and so on. So to start, you want to take your full bust and upper bust measurements.

For the purposes of this tutorial, there is a 4 inch difference in my full and upper bust. Since the 0-18 Ogden is drafted for a C cup or 3 inch difference, I will choose a size that is 1 inch smaller than my full measurement. I will then want to add a dart that will add an inch to the front Ogden pattern piece to make up the difference.

You are going to need your front Ogden pattern piece, a ruler, pencil, markers, scissors, tape, and extra paper.

Start by locating your bust apex. This is different on everyone. The easiest way is to hold it up to your body and approximate the location. You may move it up or down after sewing up a muslin, but make you best guess. Mark it will a cross.

Now draw the following 3 lines.

1 – From the apex to the hem. Make sure it is parallel to the CF.

2 – From the apex to the side seam.

3 – From the apex to the armhole notch.

Cut from the hem along line one. Continue to cut line 3, leaving it barely attached at the notch. Cut again from the side seam along line 2, leaving it barely attached at the apex.

Take another separate piece of paper and draw two parallel lines. The distance between them should be the amount you want to add to the front, divided by two. Since I want to add 1″ of volume to the front, I am going to draw the two lines 1/2″ apart.

Use these lines to separate line 1. Tape in place.

Notice that the hem becomes uneven. That is OK. As a bust gets larger, it needs extra length in the front. Redraw the hem so it is even.

Trim off excess. This becomes your new hemline.

Now to finish the dart. Measure the opening created from line two. This is your dart opening measurement. Mark the middle.

Draw a new line connecting the middle marking to your apex. This is going to be the top leg of your dart.

Measure out 1 1/2″ from the apex along this line and make a mark. This will be the end of your dart.

Along the side seam, measure down from this top dart leg, the amount of your dart opening and make another mark.

Draw your bottom dart leg from this marking to end of your dart marking (1 1/2″ out from the apex).

I went over the final dart legs in green to make them easier to see.

Take your bottom dart leg and fold it up to the top dart leg. This can feel a bit awkward in paper but you can do it.

I like to put a pin in it to keep it closed.

To even out the side seam, you are going to take a rule and redraw that side seam to be smooth. Cut along the line.

Open up the dart to see the new dart shape.

That is it! Do the same adjustment to the front lining pattern piece as well so they match.

I hope that was helpful!

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  • Reply Cheryl September 1, 2020 at 9:56 AM

    Thank you, thank you, thank you! I bought the pattern a few years ago to make a cami for a friend’s daughter. Fit her beautifully. Decided I would like to try to make one for myself (VERY different body shape between an 18 yr old and an over 60 yr old!) Started with some fabric I had on hand that I could use as a muslin and was so disappointed. Determined I probably needed a FBA but was stilled add to how to do that without a dart in the pattern. Going to try this!

  • Reply Carol in Denver September 1, 2020 at 1:12 PM

    Thank you for these detailed directions. It appears that adding a bust dart is the same process as making a full bust adjustment. Is that correct?

    • Reply True Bias September 1, 2020 at 2:38 PM

      Yes, it is. It’s just a different in the way that you need to choose the points first.

  • Reply Cindy September 3, 2020 at 2:17 AM

    Thanks so much! The part I couldn’t figure out was my sewing pattern bust size and why it was so different to bra size. it makes much more sense now…. Also fab instructions for the FBA. i love drawing the parallel lines – nifty.

  • Reply Kendal April 28, 2021 at 4:34 PM

    Is there also a tutorial for a small bust adjustment? Is there anything special other than just folding in and overlapping? How far in should one collapse the pieces for an A cup?

  • Reply Amalia May 5, 2021 at 5:29 PM

    I made my front dart (great instructions, thank you!). But now the front pattern piece has longer side seams and center fold length than the back piece. Do I just lengthen the back piece along the lengthen/shorten line until it matches the front? Thanks!

    • Reply Amalia May 5, 2021 at 6:31 PM

      Oh, never mind, I figured it out! For the benefit of other new sewers who might have this question: I realized that when the new dart I just made is actually closed, the side seams of the front and back pieces will be of equal length once again. Sewing sorcery!

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