Wondering how much water does your fish tank hold? With the help of a measuring tape and our handy fish tank volume calculator you can get a pretty accurate idea of how much water you will need to fill your aquarium, and also be able to estimate the amount of fish you want to stock.
You can use this aquarium volume calculator to find out your tank water volume in both Imperial (inches and gallons) and Metric (centimetres and litres). Just measure your tank and enter the values on the corresponding form.
Keep in mind that the value provided is the total water volume of a fish tank. Stones, filters and substrate also take up space, so if you are looking for a more accurate measurement reduce the height of the tank by your estimated substrate height.
If your fish tank has a non-standard shape, such as a triangle shaped corner aquarium, or a curved front such as the Rio Vision line, the measurements won’t be accurate. Below are some ways to get how much water your non-rectangular aquarium will hold.
Curved Front Aquariums
For aquariums with a curved front, use the average of the aquarium depth at the edges and at the deepest part in the middle of the front panel to get a more accurate measurement of the water volume.
Triangle or Corner Aquariums
Corner aquariums are just a triangle, which is close to half the volume of the corresponding rectangular shape. So you can use the calculator above, and just divide the result by 2. This will work if one of the corners of your aquarium is a 90 degrees angle.
Some corner fish tanks actually have 4 sides, but the back panel is significantly smaller than the larger panel. You can still find out the volume using this formula:
Water volume = [1/2 x (front-panel width + back-panel width) x depth] x height
This will give you the value in cubic centimetres or inches. A gallon has 231 cubic inches, whereas a litre has 1000 cubic centimetres.
Fish Tank Volume Calculator And Buying
Knowing the amount of water in your aquarium will help you decide how much fish to stock, but keep in mind that the shape of the fish tank will also affect the quality of life of its inhabitants. When choosing an aquarium keep in mind the swimming preferences of your chosen fish. An aquarium that is too deep may make seeing your fish difficult, whereas one that is too tall can cause issues for fish who require a lot of surface area for their territory.
Most people will tell you to buy as big a fish tank as you can afford and fit, however focusing exclusively in water volume is not such a great idea. A bigger aquarium can be more expensive to stock, run and keep in good shape than a smaller one, and the shape of the tank will define how easy or difficult will it be to reach the bottom for cleaning, for example. Before buying, be realistic about the physical abilities of the person who will take care of the aquarium and its placement so taking care of your fish is a fun activity and doesn’t become a chore.