how to calculate how many gallons is in the fish tank
Rectangular Tanks. Use a tape measure to measure the length of the tank. Measure the width and depth of the tank as well. Multiply the length, width and depth measurements in order to find the cubic volume.Divide the cubic volume in inches by 231, as a gallon is equal to 231 cubic inches.ectangular Tanks. Use a tape measure to measure the length of the tank. Measure the width and depth of the tank as well. Multiply the length, width and depth measurements in order to find the cubic volume.