[Mr_Pickles]

Your welcome. I feel that a scale that starts at zero (0) and extends upward from there is better as it anchors everyone to the same starting point, i.e. No Boobs - where all women start.
Just how far they go along the range gives a feeling of general size.

Review of the submitted formula for B_r:
Numerical value of cupsize * Difference in bust - waist / Height x Bandsize x Chest measurement / Weight = B_r

Using the example of Monica Mendez:
6.2 (GG) * 17 / 65" (5' 5") x 34 x 42 / 135 lbs = 22.685
However when I did the math I repeatedly got this answer:
6.2 * 17 / 65 * 34 * 42 / 135 = 17.15 and not 22.685
6.2 * 0.2615 * 34 * 0.3111
1.6213 * 10.5774 = 17.149 or 17.15

When I used my wife Kithara as an example:
The result was a value of 17.55

So Monica is 97.72% Kithara

Using my B_f formula I got:
Monica B factor of = 57.17
Kithara B factor of = 59.40

Thus Monica comes in at 96.25% of Kithara in B_f

As both women appear to be similarly buxom in shape and general size I would agree that both systems are comparable.


97.72% vs. 96.25% is rather close for two different approaches.
----------------------------------------------------
Here is the post with my Bf formula and variables:

For those wanting to calculate their own Bf value I have simplified the formula as much as possible and reduced it to using 3 base values.
Cp = the cup size of the individual expressed as 1 for A, 2 for B, 3 for C... fractions would work too, so a large C could be 3.75.
Ht = the height expressed as inches, sorry if you want it in metric cm just convert. 1 cm = 0.393701 in.
Fb = a calculated bra band factor which is the result of (18 - bra band in inches/2) so a Bd of 34 in. = (18-34/2) or a value of 1.

Now take those values and run them through this "simplified" equation: Updated from missing "Is she really big?" revisions

{Cp - [Fb - (3 - Cp) * (-50 * Fb) + 250 ] * (Ht/Bd)  / 100} + Cp + [ Fb - (3 - Cp) ] = B_f

Because I have simplified the equation it does have to come with some limitations:
1) Accuracy starts to wane at band sizes above 44 or below 28, however most are within this range.
2) Accuracy starts to wane at cups above G cup, again most are within this range.
3) Totally irrational heights will yield irrational results so a 108" or 24" height will not mean anything.
4) Although it did not have any real significance, I have removed aspects of weight from the formula.

So any generic person you would normally meet could be used.

Ok, yeah in that way a bottom to top system is better. That is pretty wild that our formula's could be that close together

[radiofredd]

I'm gonna try these formulas on my favorites and see what turns up. Results to follow.

[Nimrod]

I'm gonna try these formulas on my favorites and see what turns up. Results to follow.

I still am not happy with the Bf formula as I had to chop it up too much and by doing so introduced odd results near the two ends - very small and very large sizes. I will attempt to create a more accommodating version closer to the original formula curve fit equations still using easy to find / verify body dimensions.

Small breasts can generate negative Bf values and I would rather anchor the curves to zero as discussed above.

[radiofredd]

I find myself getting strange results. Women who I have used in the formulas are Tanya Song, Casey Deluxe, Sha Rizel, Valory Irene, Tessa Fowler (many of this ilk). The numbers shoot all over. It seems pushing some limits make the formulas useless. A formula that uses bust, band, cup and bust/waist difference all aggregated by height and weight make some sense. How to make it use a scale of 0 to 100 (?) with higher numbers representing more bust factor?

[Mr_Pickles]

I've been experimenting with a models measurement ratios (BWR, BHR, WHR) and weighting them against their vitals (Height, Weight, Cupsize). The results are so-so, nothing that grabs you and says this is the way to go, but nothing to give up on either.

[Nimrod]

I totally agree. The best test bed was to simply take the average woman and her dimensions and feed them into any formula. Then, change the cup size only and see what manner of curve is generated.

For the record the Bf formula is a linear relationship with the lower end generating negative numbers.

I am not happy with the Bf formula as it breaks down at the two extremes. The original "is she really big" formula actually did generate values between 0 and 100 as it was actually generating the percentage point in the overall population of where the individual actually sat.

It answered the question of the percentage of people she was bigger than.

The drawback was the many users where having difficulty interpreting the resulting answer. So when one got a value of 86.573 it did not have the feeling of an actual score but rather a range of people that could all share the same point.

Ultimately that had me attempt to simplify the formula but as we can see a modified version is actually worse the further from average one moves... not the best.

The Ideal Formula
As has been touched on above, the ideal formula would have the following aspects

1) Return values between 0 and 100 - so as to feel more like a score or rank and avoid odd values like (-15.5) or 985.02
2) Rely on easy to attain and verifiable physical stats - so nothing like neck diameter or length of nose
3) Be mathematically simple - allowing for quick calculation and cross-checking
4) Work for the whole range of women of all practical or realistic body types

The last criteria is the most tricky as the formula has to retain some realistic level of exactness regardless if we are talking about the petite 5'-0" athletic gymnast with an A cup, the middle-aged house wife who happens to sport an F cup, and the overweight college student who at 280lbs still only has B's...and everything in between.

Real World Factors to Consider
From several other threads here at the BEA some general realities can be used to help set up the groundwork for such a ranking / scoring formula. These include;

a) Weight actually has a very minor effect on breast size overall and oddly has a negative effect at very high values. It might be hard to fathom but being proportionally overweight only increases breast size slightly and being obese actually has a slight negative effect. This coupled with the negative effects of being underweight or emaciated essentially makes the contribution to breast size inconsequential. Given how weight can fluctuate so much, its general contribution to the topic at hand ends up being an unnecessary complicating factor. If any contribution of weight is part of the equation I suggest that it be minimized.

b) Cup size itself is a very inexact measurement. The fact that a 34G and 40D are the same volume but fit two different torso diameters suggests that just converting cups to values inherently ignores just how busty the 34G really is or that a 40E is larger than a 34G. This also points to the counter-intuitive effect of it simply taking more breast to reach the same cup size on a larger band. A 38E is bigger than a 32E, takes more breast tissue, yet will appear proportionately smaller. That is why some accommodation should be taken to render the band+cup size back to an actual volume and be part of the improved formula.

c) Meaningful results that are comparable and potentially ranking is the reason for this exercise. If set up well this could answer questions like; Who is bigger?, Is she really big?, Is this average?, Was she smaller or larger than ___?, What size could she be? or other basic question that continually appear here at the BEA.

d) Breast size will tend to clump around the average size and average body type. The calculation should make some allowances to help spread the middle out. As it could be possible to attain the same score for women who appear rather different. That was one of the side-effects of the modified Bf equation, the effect however was too great and resulted in cumbersome values at the statistical outliers.

Seeing how the B_r and B_f equations worked so similarly for rather busty women points to the fact both formulas are close to ideal.
B_r could be undermined by weight or above average waist widths.
B_f can be undone by small cup sizes and suffers from complexity.

[radiofredd]

I totally agree. The best test bed was to simply take the average woman and her dimensions and feed them into any formula. Then, change the cup size only and see what manner of curve is generated.

For the record the Bf formula is a linear relationship with the lower end generating negative numbers.

I am not happy with the Bf formula as it breaks down at the two extremes. The original "is she really big" formula actually did generate values between 0 and 100 as it was actually generating the percentage point in the overall population of where the individual actually sat.

It answered the question of the percentage of people she was bigger than.

The drawback was the many users where having difficulty interpreting the resulting answer. So when one got a value of 86.573 it did not have the feeling of an actual score but rather a range of people that could all share the same point.

Ultimately that had me attempt to simplify the formula but as we can see a modified version is actually worse the further from average one moves... not the best.

The Ideal Formula
As has been touched on above, the ideal formula would have the following aspects

1) Return values between 0 and 100 - so as to feel more like a score or rank and avoid odd values like (-15.5) or 985.02
2) Rely on easy to attain and verifiable physical stats - so nothing like neck diameter or length of nose
3) Be mathematically simple - allowing for quick calculation and cross-checking
4) Work for the whole range of women of all practical or realistic body types

The last criteria is the most tricky as the formula has to retain some realistic level of exactness regardless if we are talking about the petite 5'-0" athletic gymnast with an A cup, the middle-aged house wife who happens to sport an F cup, and the overweight college student who at 280lbs still only has B's...and everything in between.

Real World Factors to Consider
From several other threads here at the BEA some general realities can be used to help set up the groundwork for such a ranking / scoring formula. These include;

a) Weight actually has a very minor effect on breast size overall and oddly has a negative effect at very high values. It might be hard to fathom but being proportionally overweight only increases breast size slightly and being obese actually has a slight negative effect. This coupled with the negative effects of being underweight or emaciated essentially makes the contribution to breast size inconsequential. Given how weight can fluctuate so much, its general contribution to the topic at hand ends up being an unnecessary complicating factor. If any contribution of weight is part of the equation I suggest that it be minimized.

b) Cup size itself is a very inexact measurement. The fact that a 34G and 40D are the same volume but fit two different torso diameters suggests that just converting cups to values inherently ignores just how busty the 34G really is or that a 40E is larger than a 34G. This also points to the counter-intuitive effect of it simply taking more breast to reach the same cup size on a larger band. A 38E is bigger than a 32E, takes more breast tissue, yet will appear proportionately smaller. That is why some accommodation should be taken to render the band+cup size back to an actual volume and be part of the improved formula.

c) Meaningful results that are comparable and potentially ranking is the reason for this exercise. If set up well this could answer questions like; Who is bigger?, Is she really big?, Is this average?, Was she smaller or larger than ___?, What size could she be? or other basic question that continually appear here at the BEA.

d) Breast size will tend to clump around the average size and average body type. The calculation should make some allowances to help spread the middle out. As it could be possible to attain the same score for women who appear rather different. That was one of the side-effects of the modified Bf equation, the effect however was too great and resulted in cumbersome values at the statistical outliers.

Seeing how the B_r and B_f equations worked so similarly for rather busty women points to the fact both formulas are close to ideal.
B_r could be undermined by weight or above average waist widths.
B_f can be undone by small cup sizes and suffers from complexity.

Very thoughtful analysis Nimrod. I agree totally about cup size but see weight as a aggregating factor worth including. I think if you have a skinny girl with F cups, she will apppear more busty than a bigger girl with same cups. Including factors such as averages could be a very interesting and useful.

That said, I modified the Bust Factor formula to account for deviation from average cup size (2.125 in), which you provided on the "Is she really big?" thread. It seemed to reduced abnormalities in the results due to woman with very large cups.

I have started a spreadsheet with all the above formulas included.
https://docs.google.com/spreadsheets/d/1M-SQDtymIagYp9O_ZELYuLwIpc27ztcohUz2ziio2gw/edit?usp=sharing

I plugged in the measurements I knew from Boobpedia. Please forgive me if I have misunderstood the complexity of band size, bust, chest measurement and cup. I would like to have a universal understanding of this, if we are to create a useful document. If you see mistakes please comment! Again, I took the numbers from a single source (when available... Tanya Song and Danni Ashe are deleted from B.pedia) and used them to the best of my knowledge.

If you are the owner of a formula and see some mistakes in order of operation or data application, please comment. The only formula not included on this page is my amendment to the Bust Rating (Br) formula. I used the cup size # minus the average cup in inches (2.125) to reduce distortions.

I think this spreadsheet will help push this endeavor into a unified and representative factor. I envision being able to include the results on the Boobpedia site to provide the best possible understanding of just how big the models are.

[Mr_Pickles]

Ok I think I found a way that achieves a level of parity, but still differentiates the models enough to be viable. Like I said above I'm thinking measurement ratios is the way to go. So my new formula is:

Height * (BWR + BHR + WHR) / Weight * Cupsize + 5

* for cupsize I use the quarter scale, so a single cup is a .25, a double cup is .50, a triple cup would be .75   

I think it's a pretty solid formula, it highlights the right areas. So cupsize is weighted more heavily then height, weight is also a big factor in the rating; a 170 lb woman would be about three points lower then a 120 pound woman. I based my rating off of yours for Bf Nimrod (please don't be mad):

> 5   =  Small
5 - 10  = Medium
10 – 15 = Large
15 – 20 = Moderately Large
20 – 25 = Very Large
< 25 = Extremely Large

So for example Armie Field:

5' 2"
105 lbs
34-24-34
DDD

62 * (2.4118) / 105 * 4.75 + 5 = 11.7644

Armie Field is a Large

[bignatslover]

I have found all attempts at quantifying the female breast to be a fool's errand.

However, I would love to hear who ranks highest in your system.

Abbi Secraa?   Lexxi Luxxe?  Nancy Quill?  Rachel Aldana?  Susie Sparks?  Nicole Sands?

[solvegas]

I have found all attempts at quantifying the female breast to be a fool's errand.

However, I would love to hear who ranks highest in your system.

Abbi Secraa?   Lexxi Luxxe?  Nancy Quill?  Rachel Aldana?  Susie Sparks?  Nicole Sands?

None of them. Chelsea Charms and Beshine for me ! 

[Mr_Pickles]

I have found all attempts at quantifying the female breast to be a fool's errand.

However, I would love to hear who ranks highest in your system.

Abbi Secraa?   Lexxi Luxxe?  Nancy Quill?  Rachel Aldana?  Susie Sparks?  Nicole Sands?

I am working my way though the cupsizes, and am only up to F. Lexxi Luxxe would likely not even be in the top 10, because even though she has P cups, she's still almost 300 Lbs.

I am sort of picking models to do based on popularity. My current top 5 is:

1 - Alyssa Lynn: 14.4156
2 - Adrianne Black: 13.6556
3 - Aria Giovanni: 13.6136
4 - Zuzanna Drabinova: 13.5321
3 - Georgie Lyall: 13.0057

[pedonbio]

I have found all attempts at quantifying the female breast to be a fool's errand.

However, I would love to hear who ranks highest in your system.

Abbi Secraa?   Lexxi Luxxe?  Nancy Quill?  Rachel Aldana?  Susie Sparks?  Nicole Sands?

I agree with your premise, bnl, speaking as one of the fools who undertook that errand. The many complications come from the variety of different measurements that affect the outcome, which have been discussed above, and their interactions.

It's still fun to try.

[Nimrod]

I believe that this modified B_r formula is getting close, or as close as we could expect.

There are two aspects that are at odds when attempting to rate a degree of busty number.

1) It has to allow for the small or thin or light to be busty (more rare) and weigh them appropriately. Thereby giving more of a boost to them as they are expressing counter to a woman who is naturally large because they are tall, big, or heavy. Even if weight has a diminishing effect on bust size, especially at BMI's above 29.

2) It has to isolate the bust as the factor being analyzed so as to not be thrown off by an excessively heavy woman (who will be proportionately smaller of bust) yet notes that a fit but large woman has a great deal more breast tissue that a proportionately shorter woman.

It can be tricky to try and squeeze ALL WOMEN into a single formula. But, we are close.

I would mention that the formula requires 6 data points; height, weight, band, hip, waist, and cup. This may limit application as we may lack this level of detail for all subjects.

The minimum value is 5.00 with a woman with 0 cup size (flat). Not a problem, but an interesting minimum.

[Palomine]

I just enjoy this thread for its one and only picture.

[Nimrod]

This conundrum has been rattling around in my circuits for some time and I decided to revisit this problem afresh and start from scratch. The B_r and B_f formulas have been reviewed and scrutinized and neither was perfect as was discussed above and most specifically here http://forum.bearchive.com/index.php?topic=9992852.msg10324974#msg10324974

After thinking about the whole approach in a different way I believe I have resolved most of the problems that hampered the previous two approaches. For this I broke the problem down into the core focus of the calculations;

1) What is the relative size of the subject in question?
2) How does that size compare to others in the group?

Building from the problems of the previous formulas I knew that the new approach had to encompass;
a) Be mathematically simple
b) Use few variables or at least easy to obtain values
c) Produce a range or scores that "feel" representative
d) and most vexing... allow for the wide range of builds and sizes

Thinking of them as Stars:
While thinking about these criteria it dawned on me that this sort of comparative size chart for such a mix of types was very much like a star chart. This sort of chart ranks and groups stars across the whole range of star types while showing clusters of stars of similar nature even if these stars appear different individually. You will get small starts near to brown dwarfs and cool red super-giants grouped near giant but hot blue stars. This is possible because the basics of stellar dynamics are surprisingly consistent even when the resulting star can appear very different that its neighbor.

So I started to dig for those common factors that control, affect or are universal across all boobs.

Medical and Statistical Research:
After a good deal of digging I found some interesting medical statistical research showing how consistent breast tissue apportionment is across women. Additional work was done that backs these findings and it makes for some rather revealing work however dry the reading material. Body mass was an integral part of some of these medical reviews and this sent me on a side trip into the world of BMI.

Directly utilized research included;
Quantification of glands and fat in breast tissue: an experimental determination -Vandeweyer, Hertens D.
Department of Plastic and Reconstructive Surgery, Bruxelles, Belgium.

Contribution of Breast Volume and Weight to Body Fat Distribution in Females - Katch, Campaigner, Freedson, Sady, Behnke.
Department of Physical Education Research Lab, Ann Arbor, Michigan
and referenced works therein.

Building the Formula
After taking the core framework of the Bf formula which at its heart is closer to a build ratio equation I restructured the formula taking the conclusions of the medical researchers. After building out the full formula I simplified it so as to not appear as cumbersome to calculate. This was possible due to two factors;
1) The core breast mass ratio research was confirmed consistent and constant across BMIs.
2) The drawbacks of the BMI calculations actually compensate for the final calculation as they push the result to be more accurate near the extreme BMI values.

The Formula
The result of all this research produced a basic mass ratio value that is balanced to the ratio of actual BMI to baseline BMI. The result I am calling B_q or Breast quotient. Think of it as an buxom IQ level.

B_q = Percent of body that is breast mass / Ratio of Subject BMI to Group BMI
or
B_q = P_b / (SubBMI / GrpBMI)

This formula is "fed" with only 3 variable values; height, weight (for BMI) and bra size (technically 2 values)

What is my Breast Mass?
For simplification the breast mass chart can be referenced to quick get the mass of the breast. From that a ratio of breast mass to body mass is simple division to yield the P_b value. In my full calculation I actually calculated the actual volume of the breast then generated the weight of that volume. This allowed me to check the results for different ethnic groups who actually have slightly different breast densities - however as we are considering ALL WOMEN this density difference was replaced with a constant average density.

I then took a range of women with known heights, weights and breast size (both real and fake) and produced a chart showing their corresponding B_q and breast mass ratio.

These results not only produced a nice range of results but they clustered much like what had been anticipated when using a star chart approach. The average did end up very close to a score of 100 with super augmented women ranked up near 700. Nobody will score 0 in this system, a fact that I liked.

Immediate Confirmations:
From the medical research I was to expect a horizontal cluster of most women in and around the 3-5% breast mass range and again around the 8-10%. This is exactly what I got with a small transitional group both below and above the common 3-5% women. (see FIGURE 1 chart)

More Testing Followed:
More confirmations were needed as most of these women were either adult models, porn stars or noteworthy by BEA standards. Before I got ahead of myself I wanted to test this approach more to see if it actually acted as expected across all body types - a key point of the revisiting this problem anew.