To calculate volume of a rectangle, you can get cubic units by multiplying Length x Width x Height.
Dimensions in the description are
"18 INCHES TALL
9 INCHES FROM FRONT TO BACK
16 INCHES FROM SIDE TO SIDE"
thus: 18x9x16=2592
Because the measurements are in "inches" we can say if it were rectangular it would be 2592 cubic inches.
However it is NOT rectangular!
It looks like about half way along the width ("9 inches from front to back") it becomes more trapezoidal... if we solve for the cubic inches on the space that ISN'T there (in this case the triangles on the side) we can then subtract that from our previous rectangular volume of 2592 cubic inches and then apply a conversion to liters!
Oh the excitement!
Check it out
We have to make a few assumptions here but tanks are usually made with conveniently easy proportions.
If it looks to be about half way between the front and back (9inches) we know one end of the triangle is 4.5 inches
for the other side, it looks to be about 1/4th the length (we know to be 16 inches) so 16 x 0.25 = 4
If we know the triangle lengths are 4.5inches and 4inches we can use the Pythagorean theorem (because its a right angle)
a2 + b2 = c2
Thus 20.25+16=36.25
the square root of 36.25 = 6.02
So lets say your triangle is 4.5/4/6
and we know that it is 18 inches tall
so lets solve for the volume of this triangle!
Excited yet?
Because we are dealing with 2 of these triangles (right angles) lets put them together to create another rectangle (easier now that I think of it)
So we're looking at 4.5x4x18= 324 cubic inches (remember this represents the cubic volume of both the identified triangles on the sides because we put them together
So if we take our total of 2592 and subtract the "triangles" that aren't there, 324
2592-324=2268 total cubic inches! (based on our assumptions... but shhh...)
So to convert cubic inches to liters we do a multiplication of sorts.
we know, or google tells us
, that 1 cubic inch = 0.016387064 liters
THUS 2268(cubic inches) = 37.1658612 liters
WOOOO!
If it's worth doing, its worth over doing!
~Scott