How to add darts to your basic bust pattern

You may already have built your basic bodice shell without darts or you’re just curious about how to adapt a rectangular sheet of paper to your wonderful morphology. You are in the right place because we will tackle the darts issue.

Before you begin, make sure you have properly taken and recorded on a paper the following measurements:

  • breast depth
  • nipple distance
  • bust measurement
  • waist
  • hips
  • hips height

You also need your basic pattern bust without darts, a calculator and a curved line.

There are two main darts on the bodice pattern:

  • the strap dart
  • the waist darts

The strap dart
Draw the bust line at a distance equal to the bust depth of the starting point above the neck. On this line, mark the point A at a distance equal to one-half nipple distance to the middle line.

From point A, draw AB, B is the middle of the shoulder line. AB is the first branch of the strap dart.


Now calculate the value of your strap dart:
Value of the dart = 1/20 bust measurement

Draw the second branch of the dart spaced apart from the first with the value of the dart. The second branch is the same length as the first: AB = AC

To adjust the shoulder line after closing the dart, trace the shoulder at an angle of 72 ° with the second branch of the strap dart.

Extend the arm-to-arm line with the value absorbed by the dart, DE = GF, and close the armhole curve. Your strap dart is now complete.


Waist darts
Calculate the value to absorb by darts:
Value of waist darts = bust measurment – waist

This value must be absorbed on the front and back pattern, like this:
Value of waist darts = 4 * half-side darts + 2 * front darts + 2* back darts + 1 * mid back dart


Try to set values to waist darts in this order:

  • Side darts start at the armhole line.
  • Half front side dart = half back side dart . The half-side darts value must not exceed 4 cm.
  • Front waist darts start at the point A and must not exceed 3 cm each.
  • Back waist darts start to the armhole line and must not exceed 3 cm each.
  • The mid-back dart starts at the arm-to-arm line and should not exceed 2 cm.


Have some fun to add and remove centimeters to your darts values. The exercise is far from easy. Additionally, you should bear in mind that:

  • If you are very thin and your chest is barely 15-20 cm largger than your waistline, you can forget the mid-back dart.
  • If you have a very well shaped body, the darts are your best friends to highlight your curves. You might be required to add front and back waist darts to absorb the difference between the waist and chest.

It is better to keep darts value between the brackets mentioned above as giving high values can distort the garment.

Once you have assigned values to your waist darts, check again:
Value of waist darts = 4 * half-side darts + 2 * front darts + 2* back darts + 1 * mid back dart

For strap and front waist darts, observe a 2 cm flatness from point A.

For the back pattern, there is also a shoulder dart, only used for large sizes or when sewing heavy fabrics, like for coats.
It is placed in the middle of the shoulder, its value is 1 cm, its length does not exceed 7 cm.

Your bodice pattern is finished to the waist. But if you want to draft jackets or shirts you’ll need a bodice pattern to the hips.

Extend your front and back patterns with the hips height  previously measured and trace the hips line like this:

  • Front hips width =  hips / 4 + 1 cm
  • Back hips width = hips / 4 -1 cm

The hips darts should match the waist and side darts drawn before. The side line is not straight but rounded.


Your basic pattern is completed. This method is inspired by Teresa Gilewska’s, “2D Pattern-Making: the basis, vol 1”.

Copy your pattern on in-woven paper, so you can try it on and adjust it. Once you are satisfied, I suggest you to transfer it to a card and copy it whenever you draw a pattern. Don’t forget to add the ease.

I will do a separate post on how to change darts position which is much funnier and less mathematical because you will only need a pair of scissors.


30 thoughts on “How to add darts to your basic bust pattern”

  1. For example I subtracted my bust measurement from my waist and according to this post that is the valve of my waist darts, but then I don’t understand what I am supposed to do next. I guess I am having a problem in absorbing the darts in the front and back bodice. Honestly this is my first pattern and I don’t really know how to do that and I am a little confused for this part.

  2. I have tried ( several times from other sources,too) making slopers with formulaic proportions and have had very little success. Maybe it is my personal proportions but I have better results by drawing the basic bodice shape and adding the numbers from my measurements. This makes my osteoporotic stoop workable and my small bust workable. Perhaps it is just me but this way everything fits.

    • What do you mean by ” drawing the basic bodice shape and adding the numbers from my measurements”?

  3. Thank you so much. I finally found my answer to understanding the basic pattern block.
    I have a book that explains the patterns but I got confused because some patterns have darts others don’t so whenever I drafted a bodice pattern I question myself wether I should add or change something but this cleared these issues for me so thank you soo much 🙂

  4. I’m having trouble with this pattern. I’m trying to draft one for my sister but sadly she is quite obese, which brings me to a problem I didn’t expect having: her waist is bigger than her hips and bust, so I can’t add no darts apparently, and also I just realised the basic bodice pattern won’t fit her either because it’s based on bust size… is there a different way of making patterns for this kind of body? DO i have to add “inverted” darts or something? Awesome tutorial anyway, I’ve used it for me and works perfectly.

    • Thank you Isi for bringing in issues I have not thought yet. In this particular case, the baisic pattern should be built on the waist size rather than bust size. I am not sure if you need to add darts. The best option I think is to sew a canvas bust in white coton and to see if you need to add darts and where by draping the canvas on the body. I hope it helps

  5. Hi, this was a nice explanation about darts. I have a few doubts. Is it that the value of darts always 1/20 of bust? And also what will be measurement for side dart which is below arm hole? Please share more details for very beginners like me.

    • Hi Shylaja, the value of the strap dart (from the shoulder to the bust) is 1/20 not the other darts. For side darts, you need to calculate the total value of darts that you need to absorb and then set values as 1, 2 or 3 cm.

  6. Hi! I have recently taken an interest in sewing and understanding darts has been challenging to say the least. I have a question about how to have waist darts in a shirt that is a longer length (mid thigh). Is there a way to have waist darts so that only the waist is fitted and the rest of the shirt below the waist flowy?

    • I am afraid it is not possible to fit only the above waist.

  7. Your posts are very informative. I am a beginner sewer, and am having trouble manipulating my basic pattern to put a dart in the side seam and how to adjust the armhole afterwards. I tried something and then when it came to sewing it together my armholes were a terrible mess, and furthermore fitting sleeves were a nightmare. So I have two questions for you- 1) can you help me with the dart/armhole manipulation, and 2) if I want to put in a flat sleeve (woven fabric) do I make any adjustments to the sleeve cap?

  8. Pls ! The first question by honey B wasn’t answered am interested in that as I have the same problem. Thanks for sharing.

    • Well, the idea is to dispach the overall value darts between front and side darts…so you need to find the value of each dart…by trying different values and balancing them

  9. The back dart issue. After I absorb the dart value then I need to manipulate the middle back dart by shift it back to the middle? Then my middle back will be straight and my dart will be more wider in the middle?

  10. In your tutorial, you gave some set of values for dart spread which should not be exceeded in order not to distort the overall outcome of the bodice. Now, with the value of my waist dart equaling 20.5cm, it seems impossible, or rather confusing, spreading my dart value and staying within the limit at the same time. Please, i need to know how to go about this.
    Great tutorial anyways!
    Thank you!

    • Hi irene, a waist dart cannot be of 20.5 cm, this seems the be the difference between your bust and your waist, you need to divide this by 4 (as there are 2 front half-pattern and 2 back half-pattern), hope it helps

  11. your math problem left me a little confused….I am not a math person so if you could explain it in easier terms that would be great

  12. Thank you so much for the short tutorial
    But my experience so far is that anytime am done with darts on a dress especially for someone that has large hip and small waist…the dress rumbles at the end of the front dart below the abdomen when they wear the dress. Why? Please help me out?

    • Hi Tobi and thank you for the message. It is not easy to answer you as I do not quite vizualize your problemn. are you trying to tell me that the front darts between the waist and the hips are not sitting propeperly

  13. Hi thank you for the tutorial! I’ve been looking all over for it

    I just want to know whether we can just stop at the shoulder dart? Will it be incomplete if I don’t follow through the 2nd part about the waist dart?

    • you can keep only the shoulder dart if you want a straight blouse for example

  14. Wonderful tutorial, but please do you have a video channel somewhere?
    If you don’t, please do think about it. You would have a great following

    • you may be right for the video channel, everything is video nowdays, but I really enjoy writing and reading so I prefer to stay here for the moment

  15. Hello
    My main issue is that, do I make my first pattern with my normal measurement before I include darts??
    Am not sure how to really explain myself

    • that’s is true, not very clear but I will try to guess: so you take your precise measurements, you draw the slope, you add darts, you modify the basic pattern to your desired model and then you add the necessary easy.

  16. This blog is really a godsend to me. I’ve tried several more or less complex methods to make a basic bodice. None of them where anywhere near this. Although I did actually corrected second version, the first was already very very well fitted. I only played with length of darts and added mid back dart (slightly correcting my waist measurement). As a result I finally created almost second skin. Can’t wait to add ease and manipulate for countless patterns. Also, maybe that helps somebody – curving the darts may reflect individual anatomy more exact.
    Pants drafting was Oscar winning method to me as well!
    Chapeau bas, Thank you so much for your work.

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