# Blood capacity of a penis. **URL:** \ **Category:** Factual Questions\ **Created:** [November 19, 2004, 2:30pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653 "2004-11-19T14:30:14Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![flapcats](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@flapcats](https://boards.straightdope.com/u/flapcats)\ **Post date:** [November 19, 2004, 2:30pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/1 "2004-11-19T14:30:14Z")
How much blood is in an average erect penis? ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [November 19, 2004, 3:57pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/2 "2004-11-19T15:57:31Z")
Well, a friend of mine said that he couldn’t have sex because every time he got an erection he fainted from lack of blood to his brain. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [November 19, 2004, 4:20pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/3 "2004-11-19T16:20:20Z")
> [@David Simmons](#): > > Well, a friend of mine said that he couldn’t have sex because every time he got an erection he fainted from lack of blood to his brain. **Safe sex?** ---
**Author:** ![flapcats](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@flapcats](https://boards.straightdope.com/u/flapcats)\ **Post date:** [November 19, 2004, 4:21pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/4 "2004-11-19T16:21:29Z")
Could it be more than half a pint? This is to settle a debate in our studio. ---
**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\ **Post date:** [November 19, 2004, 5:19pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/5 "2004-11-19T17:19:06Z")
> [@flapcats](#): > > How much blood is in an average erect penis? African or European? ---
**Author:** ![ouryL](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ouryl/32/6067_2.png) [@ouryL](https://boards.straightdope.com/u/ouryL)\ **Post date:** [November 19, 2004, 5:25pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/6 "2004-11-19T17:25:08Z")
> [@flapcats](#): > > Could it be more than half a pint? > > This is to settle a debate in our studio. half a pint? two cups? 16 ounces? Sheesh!! A single popsicle is like 2 ozs. Imagine one eight times bigger!! Or are you guys especially endowed? ---
**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\ **Post date:** [November 19, 2004, 5:29pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/7 "2004-11-19T17:29:35Z")
> [@ouryL](#): > > half a pint? > > two cups? > > 16 ounces? > > Sheesh! Half a pint is equal to a cup, or eight ounces. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [November 19, 2004, 5:40pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/8 "2004-11-19T17:40:59Z")
You are talking about an ounce of blood, or less. Even John Holmes didn’t use a cup! (pun intended) 😃 ---
**Author:** ![zut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zut/32/2875_2.png) [@zut](https://boards.straightdope.com/u/zut)\ **Post date:** [November 19, 2004, 5:43pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/9 "2004-11-19T17:43:53Z")
Half a pint is _one_ cup, actually. A single cup is about [14.4 cubic inches](http://www.metric-conversions.org/volume/cups-to-cubic-inches.htm). Now, if we model an erect penis as a right circular cylinder – a shape which it appears to closely resemble – we can determine the volume contained therein. An average (white male) erect penis is [6.2 inches long and 3.7 inches in circumference](http://www.straightdope.com/classics/a2_193.html). Total volume is then 6.75 cubic inches, a factor of two less than the OP’s “half a pint,” and this without subtracting initial, flaccid volume (although, in my experience, there is a noticeable difference between initial and final volume). It is still possible, of course, that males with behemoth members, substantially outweighing the “average” penis, might require as much as a half pint of blood to fully awaken their trouser snake. Said member, though, would need to have a much increased length and/or cross-sectional area. Should the OP locate such a specimin, I would recommend a tightly controlled series of measurements in both possible states in order to assure accurate calculations. ---
**Author:** ![Malodorous](https://avatars.discourse-cdn.com/v4/letter/m/e47774/32.png) [@Malodorous](https://boards.straightdope.com/u/Malodorous)\ **Post date:** [November 19, 2004, 5:47pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/10 "2004-11-19T17:47:34Z")
For this fun experiment you can do at home you will need: 1 graduated cylinder An erect penis (human) Well the average volume of the human body is supposedly .1 m^3. The average amount of blood in a human is 6 quarts. Thats 60 quarts of blood per cubic meter of human. Quick!!! junior scientists, to the lab. Get a graduated cylinder fill it to the top with water, then stick an erected penis in there. If this turns you on, that’s a bonus. Pull him out and measure how much the water level dropped due to water being forced out by the volume of the penis, that’s the volume of the penis. Convert this into cubic meters (if it’s in ML, divide by a billion), then multiply this number by the average quarts of blood in a cubic meter (60) to get a rough estimate of the answer to this question. If your self-confident (or used someone elses penis), post the results here and we can have fun trying to derive your length. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [November 19, 2004, 6:04pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/11 "2004-11-19T18:04:19Z")
It of course depends a lot on size. Volume can be calculated by multiplying cross sectional area (pi times diameter) by length (using a cylinder as an approximation). Volume of blood can be estimated by subtracting the flaccid volume from the erect. For an “average” penis, let’s say the change is from 1.25 inch diameter x 3 inch length to 1.5 inch x 6 inch. That gives a volume change of about 106 cc, or about 3.5 oz. or 1/5 of a pint. For someone of Long Dong Silver’s dimension’s, let’s assume a change from 2 inch diameter x 9 inches to 3 inches x 18 inches. This gives a volume change of about 729 cc, or 24 oz, or 1.5 pints. YPMV (Your Penis May Vary) ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [November 19, 2004, 7:05pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/12 "2004-11-19T19:05:02Z")
> [@zut](#): > > An average (white male) erect penis is [6.2 inches long and 3.7 inches in circumference](http://www.straightdope.com/classics/a2_193.html) Fascinating. Do you have any data on the average white female penis? ---
**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\ **Post date:** [November 19, 2004, 7:33pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/13 "2004-11-19T19:33:58Z")
> [@kunilou](#): > > Fascinating. Do you have any data on the average white female penis? It’s generally much smaller and typically in a boat. ---
**Author:** ![ouryL](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ouryl/32/6067_2.png) [@ouryL](https://boards.straightdope.com/u/ouryL)\ **Post date:** [November 19, 2004, 10:59pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/14 "2004-11-19T22:59:49Z")
> [@ouryL](#): > > half a pint? > > two cups? > > 16 ounces? > > Sheesh!! > > A single popsicle is like 2 ozs. > > Imagine one eight times bigger!! > > Or are you guys especially endowed? OOPS!! MY BAD!! ---
**Author:** ![fortytwo](https://avatars.discourse-cdn.com/v4/letter/f/f9ae1b/32.png) [@fortytwo](https://boards.straightdope.com/u/fortytwo)\ **Post date:** [November 19, 2004, 11:33pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/15 "2004-11-19T23:33:29Z")
> [@ShibbOleth](#): > > African or European? Or Errol Flynn? ---
**Author:** ![flapcats](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@flapcats](https://boards.straightdope.com/u/flapcats)\ **Post date:** [November 19, 2004, 11:33pm UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/16 "2004-11-19T23:33:45Z")
I won’t be dipping ANYTHING into ANYTHING ELSE while at work. This isn’t just a skin-deep question: They don’t start at the front and extend 6.2in out - the penisy flesh is embedded quite a bit further into the body - how far in is that bit and how much blood does it contain? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 20, 2004, 12:00am UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/17 "2004-11-20T00:00:31Z")
> [@Malodorous](#): > > Well the average volume of the human body is supposedly .1 m^3. The average amount of blood in a human is 6 quarts. Thats 60 quarts of blood per cubic meter of human. Quick!!! junior scientists, to the lab. And get your F’s. 😃 .1 m is 3.937 inches. A bit small for a human body. Even cubed. Especially cubed. ---
**Author:** ![seosamh](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@seosamh](https://boards.straightdope.com/u/seosamh)\ **Post date:** [November 20, 2004, 12:33am UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/18 "2004-11-20T00:33:30Z")
“Half a pint?? That’s very nearly an armful!” Tony Hancock, 1959. ---
**Author:** ![Malodorous](https://avatars.discourse-cdn.com/v4/letter/m/e47774/32.png) [@Malodorous](https://boards.straightdope.com/u/Malodorous)\ **Post date:** [November 20, 2004, 12:37am UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/19 "2004-11-20T00:37:16Z")
> [@Exapno Mapcase](#): > > And get your F’s. 😃 > > .1 m is 3.937 inches. A bit small for a human body. Even cubed. > > Especially cubed. It’s not (.1 m)^3, it’s .1m^3, that is not a tenth of a meter cubed but a tenth of a cubed meter. ---
**Author:** ![Call\_me\_Frank](https://avatars.discourse-cdn.com/v4/letter/c/90ced4/32.png) [@Call\_me\_Frank](https://boards.straightdope.com/u/Call_me_Frank)\ **Post date:** [November 20, 2004, 4:25am UTC](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653/20 "2004-11-20T04:25:06Z")
> [@Malodorous](#): > > For this fun experiment you can do at home you will need: > 1 graduated cylinder > An erect penis (human) > > Well the average volume of the human body is supposedly .1 m^3. The average amount of blood in a human is 6 quarts. Thats 60 quarts of blood per cubic meter of human. Quick!!! junior scientists, to the lab. Get a graduated cylinder fill it to the top with water, then stick an erected penis in there. If this turns you on, that’s a bonus. Pull him out and measure how much the water level dropped due to water being forced out by the volume of the penis, that’s the volume of the penis. Convert this into cubic meters (if it’s in ML, divide by a billion), then multiply this number by the average quarts of blood in a cubic meter (60) to get a rough estimate of the answer to this question. > > If your self-confident (or used someone elses penis), post the results here and we can have fun trying to derive your length. Maybe I’m missing something in your post, but if the question is specifcally how much _blood_ is in the erect penis, would one not follow this procedure? 1. Insert flaccid penis into graduated beaker filled with water 2. Remove penis and measure how much water is left. 3. Subtract that measurement from the original volume of water and that’s the volume of a flaccid penis. 4. Insert erect penis into graduated beaker filled with water 5. Remove penis and measure how much water is left. 6. Subtract that measurement from the original volume of water and that’s the volume of an _erect_ penis. 7. Subtract the volume obtained in step 3 from the volume obtained in step 6 and that’s the volume of blood that was transferred to the penis to make it erect. The reason I would suggest going to these lengths (no pun intended) is because your calculation of blood/m^3 would be an average and there could be significant differences in blood/m^3 between various body parts. [Next page](https://boards.straightdope.com/t/blood-capacity-of-a-penis/275653.md?page=2)