Hi guys, today you will learn the best bust dart calculator technique for your bodice block.
Below is the bodice block template I would be referring to. I have indicated the back and front darts as shown (GG to II and EE to DD).
In this template below, the front and back have been plotted together (point M to BB is the side seam) but you can also draft them separately and still apply the dart intake formula I am about to show you.
Bust Dart Calculator For Bodice Block

Measurements We Need
To calculate the dart intake (GG to II and EE to DD), we need two measurements, the bust and the waist measurements of the person. Note that the bustier a person is the more dart intake that would be needed. The greater the difference between the bust and waist measurement, the bustier the shape is hence the need for greater bust dart intake.
In my opinion, calculating the bust dart intake using this method prevents the need for doing Full bust adjustments as you would have already incorporated the needed dart intake and shaping during the bodice block making stage.
I will use three different illustrations to explain this concept.
Example of Body Measurements For Our Bust Dart Calculator Illustration
Person 1 | Person 2 | Person 3 |
Bust: 38 inches | Bust: 38 inches | Bust: 38 inches |
Waist: 34 inches | Waist: 31 inches | Waist: 29 inches |
My Formula for Calculating The Dart Intake
We will use this formula:
(half Bust plus 1 inch ease – half waist plus ½ inch ease) plus ½ inch = X
Then allocate whatever result you get X in approximately the ratio 3:1
This is because the main difference between the bust and waist is due to the breast and this is located in the front hence we give a greater allocation of this dart intake measurement to the front.
Dart Intake Calculation
Referenced from the body measurement table above.
Person 1:
(Half bust plus 1 inch ease) =20” – (Half waist plus 1/2 inch ease)=17-1/2” = 2-1/2” plus 1/2 inch = 3”
Approximate dart allocation of the 3 inches will be front 2-1/4” (two and quarter inches) and back 3/4” (three-quarter inch)
Person 2:
Half bust plus 1 inch ease) =20” – (Half waist plus 1/2 inch ease)=15-1/2” = 4-1/2” plus 1/2 inch = 5”
Approximate dart allocation of the 5 inches will be front 3-3/4” and back 1-1/4”
Person 3:
Half bust plus 1 inch ease) =20” – (Half waist plus 1/2 inch ease)=14-1/2” = 5-1/2” plus 1/2 inch = 6”
Approximate dart allocation of the 6 inches will be front 4-1/2” and back 1-1/2”
So you can see that for all three shapes, with bust 38 inches the dart intake and allocation is different as they all have different figures. Person 3 is likely to be the figure with the fullest bust. We can deduce this from the fact that she has the smallest waist.
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