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Fish Tank Volume Calculator

Fish Tank Weight Calculator

Weight

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Enter your tank dimensions to see the volume.

Did we solve your problem?

Estimate how heavy your aquarium will be when full. Enter the dimensions to get the volume, then convert it to the weight of the water.

How tank weight relates to volume

Fresh water weighs about 1 kilogram per litre, and a US gallon weighs about 3.79 kilograms. Find your volume in litres, then the water weight in kilograms is roughly the same number. Add the glass, stand, substrate and rocks for the total.

Water weight at a glance

Drag to fill a 60 by 30 by 30 cm (54 L) tank and see how much the water weighs.

50% full β‰ˆ 27 kg of water (59.5 lb)

How to calculate fish tank volume

Measure the length, width and height of your tank, then multiply them together. Change the values below and the diagram and the calculation update instantly.

  1. 1

    Measure length, width and height

    60 x 30 x 30 cm

  2. 2

    Multiply them for cubic centimetres

    60 x 30 x 30 = 54,000 cmΒ³

  3. 3

    Convert to litres and gallons

    54,000 Γ· 1000 = 54 litres (14.27 US gal)

Formulas behind the fish tank volume calculator

Prefer to calculate the aquarium size by hand? Here is the volume formula for each tank shape. Click a card to try it in the calculator.

For unusual tanks, see a triangular prism volume tool, and note that spherical aquariums (fish bowls) are not recommended for keeping fish.

Aquarium shapes

Our fish tank volume calculator supports seven popular aquarium shapes. Click any shape to load it into the calculator above.

Frequently asked questions

How do I work out the weight of a full fish tank?
Multiply your volume in litres by 1 kilogram, then add the weight of the glass, substrate and rocks.
How much does a 200 litre tank weigh?
The water alone weighs about 200 kg, and the loaded total is often 250 to 290 kg with glass and substrate.
Is saltwater heavier than fresh water?
Yes, slightly. Salt water is about 1.025 kg per litre, so add 2 to 3 percent for a marine tank.
Why does tank weight matter?
A heavy tank needs a stand rated for the full load and is best placed against a load-bearing wall.
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.

Calculator tools

Explore our specialised fish tank volume calculators, each tailored for a specific unit, shape or region.

In Gallons In Litres Tank Size Capacity Dimensions Water Volume Tank Weight In CM In MM In Inches In Feet Metric Hexagon Corner Cylinder & Round Bow-front Triangle Octagon Pentagon Surface Area UK Australia

Related guides

Learn the core ideas behind fish tank volume before or after using the calculator.