Surface area vs. Penis Volume?

So, in summary— the bigger the better. :mona:

(so, vaginal-wall-tension (and joking) aside, length is better then girth in terms of size of area stimulated.)

Thanks, SilentRob. Glad you finally broke yours. Welcome to T’s Place.

To put it in non-math-nerd type terms, surface area is indeed a better indicator of size increase than volume.
Why? Because volume measurement overstates the growth increase by measuring what is below the surface, which isn’t important. In other words, if you were going to stick a beer bottle into a woman, it wouldn’t matter if the bottle was full or empty, it is only the outer surface she feels.

If you grow from 6x4.5 to 6x5.5, your volume increase is 50% while your surface area increases 22%. Intuitively, I think you would say that the difference between these 2 dicks visually, would be closer to 20% and NOT that the 6x5.5 is 50% more dick than the 6x4.5.

Not true. If you use the volume theory, then an increase in penis diameter adds more volume than the same increase in length. In the surface area theory, an incremental change in length or in diameter adds the same amount of surface area, which in my mind is more reflective of the real change in size.

Silent Rob, I am still thinking about this, but I think your theory is confusing 2 things. Are we looking for a measure of size increase or pleasure increase? I think the surface area is the most accurate measure of how much your size increases. Your theory assumes that girth is more important than length (which many women agree to), so therefore, volume is the measurement that emphasizes girth.
Fair enough. But let’s look at an example:
2 guys start at 6x4.5. Guy#1 works girth and gets up to 6x5.5. Guy #2 works length and achieves 7x4.5. Which guy now has the bigger dick?

Start) 6x4.5 volume = 19.3 cu in, surface = 27 sq in
Guy#1) 6x5.5 volume = 28.9 cu in, surface = 33 sq in — Change in V=49%, change in S = 22%
Guy#2) 7x4.5 volume = 22.6 cu in, surface = 31.5 sq in — Change in V = 17%, change in S = 17%

Comparison of guy#1 to guy #2 after growth:
Guy#1 is 28% bigger than guy#2 in terms of volume, and 5% bigger in terms of surface area.

Thinking intuitively again, I would say that the 6x5.5 guy does not have almost 1/3 more dick than the 7x4.5 guy has, as the volume calculation suggests. It seems more fair to say he is 5% bigger as the surface calculation says. In terms of pleasure, maybe the 6x5.5 deserves a 28% higher score. Only a woman can tell you, and I’m sure women would have different opinions about this. But that is rather subjective, to throw a “pleasure” factor into the equation. To stick to a realistic description of size increase, I would say surface area works best.

Thanks for the welcome.. I’m not sure what I broke, but seeing as it was mine apparently, I won’t worry about it =].

I was looking for the size increase measurement that would mean the better pleasure increase.. Of course that’s completely subjective. But I was basically seeing if it was appropriate to use the volume, seeing volume increases so much faster than surface area, and thus volume increases might be a bit of an inflated, or overstated, way to look at it. Again, don’t take it too seriously.

No matter how big the bore, you still have to have some stroke.

Very true, but the volume theory says you need a whole lot of extra stroke to be equivalent to a little bit of extra bore. Although it seems women often say girth is the important thing, I don’t think it is so disproportunately important compared to length as the volume idea concludes. Women can like it deep too. And when a woman talks about a guy with a “big dick”, I think it is at least as likely that she thought it was big because of the length, as the girth.

So, I think gaining length OR girth both give you an advantage, and surface area makes these 2 gains seem more equivalent, which I think is the way it should be.

I don’t want to read this whole thread again but aren’t the two sort of equal in the end? surface square inches of skin area dictating total interior volume?

T is absolutely correct; you do need some stroke no matter how big your bore. But I think that women seeing an erect one before sex are more interested in girth, calculating perhaps how that thing is going to fit or feel inside and then over-judging size based on their initial, subjective evaluation of the tool.

No Avocet. It is explained pretty well above, but to summarize, assuming your dick is a cylinder:

Surface area = circumference x length = 2*pi*radius*length
Volume = area times length = pi *radius squared*length

So, surface area increases linearly as radius increases, while volume increases by the square of radius. So volume increases much more as you increase girth compared with surface area.

You guys are so smart, mravg. Thanks for the clear-up and for the time to write it out.

But, not many of us have cylinders? Mine is sort of a round triangle, if you follow.

I definitely follow, but since it’s very rounded at the corners, we can still think of a cylinder for computations.

Think of it this way: Draw an approximate cross-section outline of a penis’s quasi-triangular perimeter, then mark a point inside of it that looks like the center. Then draw a circle such that the “sides” are inside the circle, and the “corners” are outside, with roughly the same “error” both inside and outside. This circle should have approximately the same circumference as the penis’s perimeter, and should also have an area equal to that of the actual cross section. By this approximation, we can just assume that the penis is a cylinder.

“But how do we measure the radius that we use in those formulas?” you might ask. Simple, you don’t <I>directly</I> measure the radius, you <I>derive</I> it.. You just wrap a tape measure around the outer edge to measure the full perimeter, which we at Thunder’s call “girth”. Remember: Girth = 2*pi*R. A little algebra shows that R=(Girth)/(2*pi). Since 2*pi is about equal to 6.3, divide your girth by about 6.3 (regardless of whether you measure cm or inches, since 2*pi has no units.. It’s just a number), and you have the Radius figure to apply to your volume calculation (you don’t need Radius for SA calculation, since SA = G*L).

“But my shaft’s girth is not constant.. It gets wider or narrower toward the end!” That’s why you’re encouraged to measure girth at the midpoint (for most people) or wherever the girth appears to be the average. Simple as that.

Another thing is that because we’re approximating, we shouldn’t use so many digits. I mean, it’s almost meaningless to say your volume or surface area increased by 243.7 percent when the formula you were using wasn’t quite that precise to begin with. But as long as you use approximate percentages, like “60% increase in SA” or “120% increase in volume”, your claim should still be fairly accurate.

It’s kinda like when you hear your friendly fascist government boast about 3.4% GDP growth and 4.7% increase in median family income last year, when the input data was derived from telephone surveys and thus is probably only accurate to within 10%. In those cases, the growth figures don’t mean anything. In science courses, they call this the “principle of significant figures (or digits)” or “appropriate error,” among other terms. Hope that helps.

Jeez, I start with a simple one-line reply, and end up slamming out 3/4 of a page. Crazy.

Ok, Dangleman, you asked the question, so what do you think now that you’ve heard the answers?

Woops, I now Realize this thread is really old. Dangleman hasn’t been around for a while.

Easy Rob. You’re becoming a post whore ;)