An aquarium is a glass-sided tank, bowl, or the like, in which fish or other living aquatic animals or plants are kept and displayed.

In most cases, aquariums have rectangular bases and therefore, to calculate for its volume, we will use the formula to find the volume of a rectangular prism.

**Formula to calculate the volume of an aquarium.**

The height also known as the depth of the aquarium in this case, refers to the height of the inner surface. So if the inner height has not been provided but you have the outer height and the width of the aquarium wall, subtract the width of the tank walls from the outer height to determine the inner height.

**Example:**

Calculate the volume of an aquarium whose length is 25 m, its width is 20 m and its inner height is 30 m.

The volume of the aquarium is 15,000 m³.