4,000 cubic feet is 29,922.08 US gallons.
100*20*2 = 4000 cubic feet
At are 7.5 Gal per Ft3
100 cubic feet = 623 Imperial gallons.
25 cubic yards is 675 cubic feet.
28,000 US gallons equates to 3,743.1 cubic feet.
7.481 gal - 1 cu ft; 17,000 gal = 2,272.42 cu ft
1 Imperial gallon = 0.1605 cu ft (to 4 dp) 1 US gallon = 0.133681 cubic feet
4,000 cubic inches = about 2.315 cubic feet.
It doesn't make sense to convert between cubic measure and square measure.
Gallons are a unit of volume. Feet are a unit of length. You can convert gallons to cubic feet. There are 7.48 gallons per cubic foot of water at 68 degrees Fahrenheit.
.5 ft x 4 ft x 6 ft=12 cubic feet 12 divided by .13368=89.76 us gal or 12 div by .16054=74.75 imperial gal
That would depend on how tall it is. For example, a house with 8 foot tall ceilings and 4000 square feet floor space, would hold:(4000 ft2)x(8 ft) = 32000 ft3If it had 10 foot ceilings, then: (4000 ft2)x(10 ft) = 40000 ft3