How Many Ping-pong Balls Can Be Kept In An Air Boeing?

I'm afraid the calculations of "conviction" above are incorrect.

Regulation ping-pong balls are 40mm, with a volume of about 2 cubic inches. You can't pack spheres much more efficiently than in a face-centered cubic arrangement, which still leaves about 26% empty space. So each ping-pong ball really needs 2.7 cubic inches. A cubic foot equals 1728 cubic inches, and would hold 640 balls. A Boeing 747 is about 230 feet long and the body diameter is about 20 feet, which works out to a cylindrical volume of roughly 72,000 cubic feet, or 46 million balls. However, the body isn't perfectly cylindrical, and it's not empty. If you still want the plane to fly, you're limited to Boeing's maximum cargo capacity (for a 747 freighter) of about 27,000 cubic feet, or 17 million ping-pong balls.

The answer below of approximately 17M seems well reasoned. (For what it's worth, I came up with 16.7M, nearly the same as below.) Also worked on same question re. A phone booth, and figured it the same way: Approximately 6 ppb's per foot; therefore 6 x 6 x 6 = ppb's per cubic foot = 216. IF the phone booth were 4 ft by 4 ft by 7 ft, then you could do this as follows:

(4 x 4 x 7) x 216 = 112 cubic feet x 216 ppb's/cubic ft = 24,192 ppb's

I don't know for sure, but you can bet it's more than 1,958. That may cover the floor of the cabin which may be 225 feet. But you have to fill up the plane, so you have to take it's height and width into consideration. My quest is that a boeing 747 would hold hundred of thousands, if not more.