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This aquarium volume calculator is pretty straight forward, just click a button above, input your measurements, and acquire results of your aquarium’s water capacity in US Gallons. This will give a rough estimate of your aquarium tank size. If you’re looking for standard aquarium sizes based on dimensions, follow this link. There are instructions below if needed.

Rectangular Aquariums

If your aquarium is in the shape of a rectangle, click the rectangle button. The prompt will ask you to provide your length, width and height in inches. Doing so will provide a rough estimate of how much water volume is in your fish tank in US gallons. Amount of gallons may differ depending on the amount of gravel and decorations in the fish tank.

Cylindrical Aquariums

If your fish tank is in the shape of a cylinder, which is quite common for vases and jars, click the Cylinder button. The prompt will ask you to provide your height and radius in inches, of the cylindrical aquarium. Radius is half the width of your tank. You can always find the diameter (full width) and divide the diameter by 2 to find your radius. The result will be the volume of your aquarium in US gallons. Actual volume may differ depending on decorations and gravel present in the fish tank.

Hexagonal Aquariums

If you have a hexagonal fish tank, click on the Hexagon button. The prompt will ask to provide length of one side of the hexagon. It will also ask for the radius of your hexagon tank. To figure this out, simply measure the length from one side of your fish tank to the other and divide that number by 2. Lastly, the prompt will ask to provide the full height of your aquarium. Each measurement should be in inches. The result will give a rough estimate of your total volume in US Gallons.

I am striving to provide measurement for other aquarium tank sizes such as bowfronts. I will share the information here in the future. If you would like to see dimensions of standard aquariums, check out this page.