20 shapes
Aquarium Volume Calculator by Shape
Pick the shape that matches your tank from above. Every calculator takes inside measurements in inches or centimetres and returns gallons, litres, cubic volume and filled weight.
No shape matches “”. See the shape guide.
Standard Tanks
Standard tanks are rectangular prisms: four vertical walls at right angles and a flat floor. They include the everyday framed tank...
Curved Tanks
Curved tanks have at least one panel that is not flat. Cylinders and bowls are fully round, while bow fronts, bullnose and round e...
Corner Tanks
Corner tanks have two straight panels that meet at a right angle so the tank can sit against two walls. What differs is the front:...
Polygon Tanks
Polygon tanks are built from flat panels arranged around a centre. Regular polygons have equal sides and need only one panel width...
Custom Shapes
Custom tanks are built to fit a space rather than a catalogue. Most can be broken into rectangles, triangles and arcs. The L-shape...
How to choose the right calculator
Look at the tank from directly above and compare its footprint with the icons. The decisive questions are: is any panel curved, do two sides meet in a corner at 90 degrees, and are all the panels the same width? Flat panels at right angles mean a standard tank. One curved panel means bow front, bullnose or half cylinder. Equal panels around a centre mean a polygon. If you are still unsure, the shape guide walks through each one with a description.
Formula summary
Every calculator multiplies a floor area by a height. The floor area is what changes with shape: L × W for a box, π × r² for a circle, 2.598 × s² for a hexagon, and so on. The formulas page lists all twenty with worked examples.