# What are the dimensions of a cube that will hold 100 lbs of water? **URL:** \ **Category:** Factual Questions\ **Created:** [June 22, 2002, 5:53am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407 "2002-06-22T05:53:30Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 22, 2002, 5:53am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/1 "2002-06-22T05:53:30Z")
I had a discussion with a friend last night of just how big a cubic box containing 100 lbs of human fat would need to be. I’m assuming human fat and water have approximately the same density (I know it’s not perfect but IIRC it’'s very close). I could do the conversion factoring (ie 1cc = 1 gram of weight) but it’s late and I’m tired. Does anyone have a direct conversion factor for lbs of water to cubic feet of volume? ---
**Author:** ![Ned](https://avatars.discourse-cdn.com/v4/letter/n/848f3c/32.png) [@Ned](https://boards.straightdope.com/u/Ned)\ **Post date:** [June 22, 2002, 6:17am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/2 "2002-06-22T06:17:24Z")
62.5 lbs per cubic foot but fat is lighter than water. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [June 22, 2002, 6:20am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/3 "2002-06-22T06:20:22Z")
A cubic foot of water weighs about 62.5 lb. Fat is about 10 or 20 percent less dense than water. Human adipose tissue consists of fat, water, and other stuff and has a denisty somewhere around 60 lb/ft[sup]3[/sup] ---
**Author:** ![Earthling](https://avatars.discourse-cdn.com/v4/letter/e/90db22/32.png) [@Earthling](https://boards.straightdope.com/u/Earthling)\ **Post date:** [June 22, 2002, 6:23am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/4 "2002-06-22T06:23:19Z")
In rough numbers: 1 gal. of water = 8.3 lbs 1 gal. = 231 in[sup]3[/sup] Therefore, 100 lbs water = 12 gal. = 2770 in[sup]3[/sup], or about 14 inches on each side. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [June 22, 2002, 7:19am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/5 "2002-06-22T07:19:31Z")
Or: 100 lbs equals 45359.237 grams, or cubic centimeters of water. The cube root of 45359.237 cubic centimeters is 35.6633317 centimeters or About 14.040682 inches. ## Tris But fat floats. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 22, 2002, 10:00pm UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/6 "2002-06-22T22:00:01Z")
Thanks! ---
**Author:** ![Patricinus\_Scriblerus](https://avatars.discourse-cdn.com/v4/letter/p/f07891/32.png) [@Patricinus\_Scriblerus](https://boards.straightdope.com/u/Patricinus_Scriblerus)\ **Post date:** [June 22, 2002, 10:55pm UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/7 "2002-06-22T22:55:31Z")
This would be soooo much easier if it were METRIC!!! ---
**Author:** ![Hello\_Again](https://avatars.discourse-cdn.com/v4/letter/h/85e7bf/32.png) [@Hello\_Again](https://boards.straightdope.com/u/Hello_Again)\ **Post date:** [June 22, 2002, 11:53pm UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/8 "2002-06-22T23:53:35Z")
A pint’s a pound, whole world 'round. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [June 23, 2002, 5:08am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/9 "2002-06-23T05:08:43Z")
You can convert to metric [here](http://www.digitaldutch.com/unitconverter/) and then report the answer back without showing your work, and look so smart. ## Tris Rule of Reason: “If nobody uses it, there’s a reason.” ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [June 23, 2002, 5:15am UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/10 "2002-06-23T05:15:36Z")
And a pint is 1.043176 pounds, in the US, but in UK it is 1.252802 pounds. ## Tris “It is when I struggle to be brief that I become obscure.” ~ Horace ~ ---
**Author:** ![SCSimmons](https://avatars.discourse-cdn.com/v4/letter/s/e495f1/32.png) [@SCSimmons](https://boards.straightdope.com/u/SCSimmons)\ **Post date:** [June 23, 2002, 2:56pm UTC](https://boards.straightdope.com/t/what-are-the-dimensions-of-a-cube-that-will-hold-100-lbs-of-water/115407/11 "2002-06-23T14:56:28Z")
> [@](#): > > \*Originally posted by Triskadecamus \* > \*\*About 14.040682 inches. \*\* You know, when you calculate your response to six decimal places, you don’t need to preface the answer with ‘about’. 😃