The calculators below can be used to calculate the volume of water in square, rectangular or cylindrical aquariums . Water volume is needed to ensure you treat your aquarium with the correct dosage of medication and fish stocking levels.

The total tank volume figure computed is a rough estimate and only takes into account your fish tank dimensions. It does not take into account ornaments, decorations, the substrate, equipment, etc. These items can have an effect on the total volume of water in your aquarium. This calculation is simply based on an empty tank with the given dimensions.. Make a minor allowance (approx 10-15%) for such things.

If your tank is not rectangular, such as a bow front (sometimes called euro style) or hexagonal tank, you can use the average of the questionable dimension to calculate your volume. For example, if your hex tank is 10" wide at the narrowest and 14" wide at the widest, you can use the average of 12" for the width to get a good idea of the volume of your tank.

*Please note: The aquarium calculators on this page use JavaScript. It will only work if JavaScript is enabled in your internet browser.

If your tank is square or rectangular:
Your tanks Length (inches):
Your tanks Width (inches):
Your tanks Depth (inches):
Your tank holds about: Gallons
If your tank is round or octagonal:
Your tank's Diameter (inches):
Your tank's Depth (inches):
Your tank holds about: Gallons
Your tank weighs:
Your Tank's Capacity (gallons):
Your tank weighs approximately: Pounds (plus substrate, rock and driftwood)

Another aquarium volume calculator can be found here. You will need to register, but it is a good website.