Aquarium Volume Calculator
Calculate realistic water volume, gross volume, surface area, and water weight with fill-gap and displacement controls.
Aquarium dimensions
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Substrate, decorations, and space above the water reduce the amount of water your aquarium holds.
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Aquarium Volume Calculator FAQ
Should I use inside or outside aquarium dimensions?
Use inside dimensions whenever possible. Glass thickness can noticeably change the real water volume, especially in smaller aquariums.
Why does substrate reduce water volume?
Substrate takes up physical space. The calculator subtracts substrate depth and fill gap from the water column before estimating usable water volume.
How accurate is the hardscape offset?
The offset is a practical estimate for rocks, wood, internal filters, and equipment. For dosing, a conservative estimate is usually better than using gross volume.
How much does aquarium water weigh?
Freshwater is close to 1 kg per L. Saltwater is slightly denser, so the calculator uses a higher weight estimate when saltwater is selected.
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