April 1, 2014

How to do a Full Bust Adjustment and add a dart on a non-darted top or dress

Did you know that most sewing patterns are drafted for a B or C cup size bust (with a few exceptions like Cashmerette Patterns which go up to an H!) , but the average woman is a DD? But don’t worry – it’s possible to adjust any sewing pattern to make the bust size bigger, in a few steps, using a Full Bust Adjustment.

This tutorial is specifically for dresses or tops that don’t already have a dart in them, so it adds the space you need as well as a new dart. It works for patterns like the Sewaholic Belcarra Blouse, the Megan Nielsen Eucalypt top/dress, or the Grainline Scout.

1. Calculate how much additional width you need through the bust. 
The quickest way to do this is to measure your bust, and work out how much bigger it is than the pattern. Then, divide that by two (because you’ll be adjusting both sides!). An alternative way is to measure your high bust and use the pattern from that size, and then add the difference between your full bust and high bust.
2. Mark your apex on the pattern.
Yeah, your apex is your nipple (cue my Google searches going mental). Place the pattern against yourself, making sure the shoulder and side seams are in the right place, and mark it on the pattern.
How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress

3. Mark three lines coming out of the apex

The first one should go from the apex up to the armhole, about 1/3 of the way up. The second should go vertically straight down the pattern from the apex. And the third goes at a gentle angle toward the side seam (you can just judge the angle by eye).

How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress
4. Start cutting and spreading!
– Cut up the vertical line, angling at the apex to the line that goes to the armhole. However, make sure you stop just before the seam allowance (usually 5/8 inch in). Then make a little snip on the other side of the seam allowance, forming a hinge
– Then, cut the line from the side seam to the apex, and again stop just before the apex to form a little hinge
– Either pin or tape down the right hand side bit of the pattern
– Now “spread” the other pieces to the left, keeping the vertical pieces parallel. Separate the vertical pieces to the additional width that you need to add. As you do this, a dart will start forming magically at the side seam!
How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress
5. True up the length
You’ll notice that the pattern is no longer lined up at the bottom. To address this, make a horizontal cut in the right hand side piece (it doesn’t matter where), and slide that piece down so that the bottom is parallel again.
How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress
6. Trace that baby!
Put some tracing paper over the chopped up pattern and trace the new outline. The triangle at the side seam is your new dart. Depending on how much you added, you may also need to re-draw the armhole using a French curve to get it back to the right shape.
How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress

7. And here we are!

The adjusted piece. Sew up the dart before you sew up the rest of the dress, and the Tank Dress will suit you oh so much better!

How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress
I hope you found this helpful – I have to FBA almost all my patterns, so I can tell you it only takes a few minutes when you have some practice!
How to do a full bust adjustment and add a dart on the Sew Caroline Tank Dress


How to do a Full Bust Adjustment on a non-darted top or dress

43 thoughts on “How to do a Full Bust Adjustment and add a dart on a non-darted top or dress

  1. Janet says:

    Thank you for the FBA. I get discouraged sometimes because I have to do them too. I appreciate you making it look easy peasy.

    1. Jenny says:

      You’re welcome! I just did a super difficult one on a wrap dress with pleats but the principles are pretty much the same 🙂

    2. Debbie Morgan says:

      Thank you that’s real easy to understand and follow.Being big busted is a very big problem.Having to buy bigger sizes accentuates the bust.Now I’m understanding a pattern more.Couldnt be more simple

      Thank you

  2. Gisella says:

    That looks very useful!
    I have learnt to love the FBA – I do them all the time now. Instead of hoping that the pattern will fit me if I take the size with the correct bust measurement (and blindly go for it), I now pin the pieces together, slip it on and then do the FBA as per the gap. The more often you do an FBA the easier and quicker it is!
    And even better: it gives you the confidence to attempt other adjustments. So very satisfying to sew to the right measurements and come up with something that fits!
    Thanks lots for these pics – I had been a bit wary of trying to FBA a dartless dress. This looks very do-able! Thanks so much!

    1. Jenny says:

      Love the FBA! We should totally get badges made 🙂

  3. sew rachel! says:

    Nice! I bet this would be helpful for my Megan Nielsen Eucalypt tank, too!

    1. Jenny says:

      Yeah, this approach should pretty much work for any dartless top! Let me know how it goes 🙂

  4. that’s the most logical and useful bust adjustment tutorial I have seen – I am about to embark on one soon and was so pleased to see such a useful one on your blog.

    1. Jenny says:

      Glad it was clear! I haven’t done many before 🙂

  5. I am always having to make a FBA and I love your tutorial. It is clear and concise. This gives me hope of getting one garment right! And I loved your Tank Dress, the fabric is fabulous and the fit is great.

    1. Jenny says:

      Thanks very much!

  6. Lisaleh says:

    Thanks for the great tutorial. I just used it for my first FBA (on the Scout Tee). I’m going to sew it up now. Cross your fingers for me!

    1. Jenny says:

      Oooh let me know how it comes out!

    2. Lisaleh says:

      Hi Jenny! Sadly, it didn’t work well. The bust darts are well positioned, but I have, like, 6 inches of extra fabric in the front centre. I don’t get it? I’m so frustrated!!!

    3. Jenny says:

      Hi Lisaleh – that may be a measuring issue. Did you halve your “width to be added” measurement? What i mean is: If the pattern is 44″ and you are 48″ bust, then you need to add 4″ overall. However, the pattern is in halves, so actually you only want to add 2″ to the pattern. That *could* be the source of your issue, perhaps? If not, the other thing you could do would be to re-work out the width you need to add by another method – one is to hold the pattern piece up so that it matches your shoulder and sides, and see how far away the pattern piece is from your center front – that’s another way to calculate it. Let me know if any of those work! You can also email me at cashmerette@gmail.com if you have photos and I can try to help 🙂

  7. jessica says:

    Thank you!!! After having my daughter, I have ignored my patterns from independent designers because they don’t have the dart for a better fit. I may try this out on one of my indie patterns I recently won. 🙂

    1. Jenny says:

      I know, I’m always amazed at anyone who can wear things without darts! Give it a go, and let me know how it goes!

  8. how do you know how much width to add?

    1. Jenny says:

      Hi Pamela – you can calculate how much width to add in three different ways. The easiest is to look at the bust measurement on the pattern (say, 44″), then compare it with yours (say, 46″). So, you need to add 2″ then, and as the pattern is just one half, you would add 1″ to the pattern. The other option is to make a muslin of the closest size to yours (say the 44″). Then, when you have it on, cut through the muslin over the fullest bit of your bust, and pull the centre of the muslin to your own center line. See how much of a gap there is in the muslin, and add that much. Personally, I do the first way.

    2. Jenny says:

      THe third is more complicated so I won’t even spell it out 🙂

  9. Jane says:

    Thanks so much for this, it’s the clearest FBA tutorial I’ve seen! x

  10. I echo the other comments. I’ve always struggled with just how much to add in a FBA…am currently repeated banging head to table…you’ve switched on a long-dimmed lightbulb in my head.

  11. Nakisha says:

    I’ve been looking for a way to add a dart to a woven top without one.

  12. I’m scared of the FBA but this makes it very clear. I’m going to give it a go now. Thanks so much!

    1. Jenny says:

      Once you figure it out, there’s no going back! 😀

  13. This is a very good tutorial. I think it’s the simplest one I’ve seen. Just to be clear. If I have a 44 inch high bust, I can use a 44 pattern and do my full bust adjustment(of a million inches) from there? I’ve been sewing for my daughter for a while and I’m hoping to take the plunge into my own garments soon but it’s SO hard to find patterns in my size.

    1. Jenny says:

      Hi Bernadette! It depends a little on your shoulder-bust ratio. If you have narrow or small shoulders and a large bust it’s better to start with the high bust, so it will still fit you in the shoulders. However if you have normal to wide shoulders/upper body (like me!) j find it easier to start with the closest size to my full bust measurement and add the difference from there. So options are 1) add the pattern size – high bust measurement 2) add pattern size – full bust measurement. Generally the less you add the more successful it will be!

  14. Thank you! Most tops are too wide in my shoulders-the shoulder seams hit on the outside of the shoulder curve. I have 4 inches difference between my high bust and my bust measurement so I’d be adding a lot.

    Sewing for myself is an intimidating task. I suppose I’ll just have to give it a go and see waht happens. I foresee a lot of muslin in my future 😉

  15. Jamie King says:

    My first FBA ever was a great success thanks to your instructions! This is going to make a huge difference in my sewing! Thank you so much!

  16. Gill says:

    This sounds great, will give it a go. Jenny, have you had any experience / or done tutorials to provide guidance for dresses that have panel fronts?

  17. Holly says:

    I have just finished making the fba, but before I make another copy, I’m going to make a muslin first. It’s a Japanese pattern…and well I’m far from thin and willowy. I really hate to spend more on the darn tracing paper than on muslin! Thanks for the instructions. I appreciate you doing it on a red back ground.

  18. NeverJustJennifer says:

    In step four you say to add the width needed. How do I know how much I’ll need?

    1. That’s explained in step 1!

  19. Anon says:

    Thank you!!! I have narrow shoulders and have had to choose to fit my shoulders and waist or my bust. This seems easy! Cannot wait to try it!

  20. deknits says:

    Thanks for the tutorial! I want to try this technique for my next Scout Tee. I’m wondering, though – does your final dart go all the way to the apex? Most information I’ve seen says that a dart should end slightly before the apex.

  21. Cheryl says:

    Thank you for this tutorial !! I just followed it to adjust the bust for Vogue 1312. I had made a new drawing based on my full bust which is 48″ of the size 24 but I pattern fit it to my dress form and it seemed too big. I decided to go with cutting the pattern for my high bust which is 42″ or the size 20. I used some cheap fabric and sewed up the bodice…fast forward,,,it failed but it was an excellent first effort. It seems like I should have gone with the full bust. Also I probably should have tried the FBA on a different pattern. This one is not meant for square shapes and I am pretty square ! The fit is not THAT bad. The dart should have come up higher under the arm and I have to be more careful with the apex placement but I can put the bodice on and with Spanx there is controlled bulging. What change can I make that will work here ? The shoulders and upper chest fit great. It gaped a little too much under the arm but I think that would be helped with the dart placement. Maybe an extra 1/2″-3/4″ spread beyond the 2″ I did add ? The bodice did smash my breasts a bit. I used the formula Full-High-2 divided by 2.

  22. Jo W says:

    Hello, hope you can help… I’ve never attempted a FBA before, but I’d really like to have a go as there’s quite a difference between my waist and bust, so I always struggle to get a good fit. I’ve previously made the Burda 2561 blouse and it’s pretty good, except the buttons gape just a bit. The pattern doesn’t have a bust dart, but it does have a waist dart, so I’m a bit confused as to how to firstly add the bust dart, then do the FBA. Any tips and info much appreciated. Thanks, Jo

    1. Jo W says:

      Oh, just to add that the tip of the vertical bust ends right on my bust point, so that dart would surely get in the way of the adjustment?

  23. Darlene says:

    Thanks for making this sound so easy to do. I recently came back to sewing for myself again and it’s been nothing but a struggle trying to do the FBA. I now understand what I can do when there is no dart to begin with. I can’t wait to try this.

  24. barb says:

    The first time I did this I marked my bust apex( say 9 inches apex to apex, or 4.5 inches to center fold)) on the not yet adjusted piece. I did the FBA steps and yeah, I ‘opened up’ the pattern ( 2 inches each side) and sewed it up. Sewn garment had fabulously fitted armholes BUT funny little pointy things to the armhole side of each boob! Alas! Boob points 13 inches apart! Argh! So I added a step.. wherein I moved both apexes( I never knew I had apexes!) back to being 9 inches apart after the FBA. Then I softened this by drawing in sewing darts with tips 10 inches apart. ( 5 inches from center fold. Perfection. You got me 99% of my way along this journey! Thanks! So fabulous to be able to do this!

  25. Your first sentence, “Did you know that most sewing patterns are drafted for a B or C cup size bust (with a few exceptions like Cashmerette Patterns which go up to an H!) , but the average woman is a DD? ” really hit me. WHY is this still the case? DD has been average for about 20 years, yet RTW clothes still are drafted for B/C and so are all patterns from the big 4 companies. A few pattern lines offer up to DD, but that clearly shows they don’t understand that if Average is DD that there can be just as many I/J cups as there are AA/A size. I’m up in the I/J range, so I’m very thankful for having found Cashmerette patterns since they fit me with only minor adjustments (I’m very tall, with very long arms and legs, so I have to lengthen everything). I love it that I even can have a bathing suit that actually fits and looks great on me 🙂

Let me know what you think!