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.
1 Imperial gallon = 0.1605 cu ft (to 4 dp) 1 US gallon = 0.133681 cubic feet
7.481 gal - 1 cu ft; 17,000 gal = 2,272.42 cu ft
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.
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
1 cu ft ≈ 6.22884 imp gal → 72 million cu ft ≈ 72 million × 6.22884 imp gal ≈ 448.5 imperial gallons 1 cu ft ≈ 7.48052 US gal → 72 million cu ft ≈ 72 million × 7.48052 U gal ≈ 538.6 US gallons