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Fish Tank Volume Calculator

Pentagon Fish Tank Volume Calculator

Volume

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Enter your tank dimensions to see the volume.

Did we solve your problem?

Calculate the volume of a pentagonal aquarium. Enter the side length and height and get the capacity in litres and gallons.

How pentagon tank volume works

A regular pentagon has five equal sides, and its area is about 1.720 times the side squared. Multiply that by the tank height for the volume, which the calculator computes automatically.

Example sizes and volumes

Side (cm)Height (cm)LitresUS gallons
154015.54.1
205034.49.1
256064.517
306092.924.5
3570147.539

Calculated with the same formula as the calculator above. Values are rounded.

Shape preview

Adjust the size and height to see this tank shape and its volume.

Volume ≈ — litres

Formula

V = 1.720 × side² × height

Related calculators

Hexagon Corner Cylinder & Round Bow-front Triangle Octagon

Frequently asked questions

How do I calculate pentagon fish tank volume?
Enter the side length and the height. The calculator uses the regular pentagon area times height.
What is the side length of a pentagon tank?
It is the length of one of the five equal straight edges, measured on the inside of the glass.
How do I get pentagon volume in gallons?
Find the volume, then switch the result unit to US or UK gallons.
Where are pentagon tanks used?
They are often corner display tanks, fitting a five-sided footprint neatly into a room corner.
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.