It's a 29 Gallon tank. You can figure out gallons from cube inches here: http://www.metric-conversions.org/volume/cubic-inches-to-us-liquid-gallons.htm or you can see a tank with same measurements here: http://www.myfishtank.com/ProductDetails.aspx?productID=7#
The volume of that space is 30" x 12" x 18" = 6,480 cubic inches = 28.052 gallons.
There's no way I can tell how much water might be in it.
There are 231 cubic inches in a gallon of water, so 48x18x7=6048 cubic inches, and 6048/231= approximately 26.2 gallons.
48in x 19in x 11.5in = 10,488in3
1 US gallon = exactly 231in3.
10,488in3 x (1gal/231in3) = 45.403 US gallons (rounded to three decimal places)
24x12x15 is about 18 US gallons, and a 36x15x18 is about 42 US gallons
2400
A tank of 21 inches wide, 8 inches deep and 59 inches long will hold 36 gallons of gas. These gallons refers to US gallons.
About 38.82 gallons for every inch deep .
2 mi2 x 2 in = 9.293x106 ft3 = 6.951x107 gallons
Up to 17.4 gallons.
489.76 gallons of water.
One US Gallon has 231 cubic inches, and the area that you've given is 36 cubic inches. So, 36/231 gallons is the exact answer, which is approximately .1558 gallons (15.6% of 1 gallon)
40 square feet * 2 inches = 40*(1/6) = 6.66... cubic ft = 41.5 UK gallons or 49.9 US gallons (approx).
About 4,650 gallons.
Assuming it is a rectangle, 56.232 imperial gallons
104834in cubed is 453.83 US gallons
16.32 US gallons.16.32 US gallons.16.32 US gallons.16.32 US gallons.
About 17,204 gallons.