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Read more →Fish Tank Volume Calculator in Gallons
Volume
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Enter your tank dimensions to see the volume.
Did we solve your problem?
Work out your aquarium volume directly in US and UK gallons. Pick your tank shape, enter the dimensions, and the result is shown in gallons instantly.
Calculating fish tank volume in gallons
To find gallons, calculate the volume in cubic inches (length times width times height in inches) and divide by 231 for US gallons or by 277.4 for UK gallons. This calculator shows both at once so you never mix them up.
Volume at a glance
Drag to fill a 60 by 30 by 30 cm (54 L) tank and watch the volume change.
50% full = 27 L
Formula
V = length × width × height Related calculators
Frequently asked questions
How do I calculate gallons in a fish tank?
Multiply length, width and height in inches and divide by 231 for US gallons, or by 277.4 for UK gallons. You can also calculate litres and multiply by 0.264 for US gallons.
Are US and UK gallons the same?
No. A US gallon is 3.785 litres while a UK gallon is 4.546 litres, so the same tank shows two different gallon figures.
How many gallons is a 60x30x30 cm tank?
It holds 54 litres, which is about 14.3 US gallons or 11.9 UK gallons.
How do I convert litres to gallons?
Multiply litres by 0.264 for US gallons, or by 0.220 for UK gallons.
What units can I use in this calculator?
You can switch between centimetres, millimetres, inches, feet and metres at any time. Enter all dimensions in the same unit and the result updates instantly.
Does the result include substrate and decoration?
The figure is the full internal capacity. Subtract roughly 10 to 15 percent for substrate, rocks and the gap you leave at the top to estimate the real water volume.
How accurate is this fish tank calculator?
It uses the exact geometric formula for each shape, so the result is accurate for the dimensions you enter. Measure the inside of the tank for the best accuracy.
Is this calculator free to use?
Yes. It is completely free, needs no sign-up, and works on phones, tablets and desktops.
Related guides
Learn the core ideas behind fish tank volume before or after using the calculator.
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