Aquarium volume calculator
Pick the tank shape and enter the dimensions. You get the volume in litres and gallons, an estimate of the water you actually have, and its weight.
Volume
Enter the dimensions to see the volume.
Runs entirely in your browser. Nothing you enter is sent to a server.
How it works
Knowing the real water volume matters when you dose water conditioner or medication, choose a heater and filter, and plan water changes. The figure on the box is usually the total glass volume; the water you actually treat is less.
Measure the inside dimensions if you can, since glass thickness noticeably reduces small tanks. For a bow-front, enter the depth at the sides and at the centre of the bow: the curve is approximated as a parabolic segment, which is close for typical bows. For a hexagon, enter the width of one side panel; a regular hexagon is assumed.
Actual water volume subtracts the substrate layer and, if you tick the option, about 10% for rock and decor. Fresh water weighs about 1 kg per litre (8.34 lb per US gallon). Glass, substrate and the stand come on top of that, so check that your furniture and floor can carry the full weight.
Frequently asked questions
Use the actual water volume for medication and fertilisers unless the label says otherwise. The total volume is useful for comparing tank sizes.
A US gallon is 3.785 litres and an imperial (UK) gallon is 4.546 litres, so the same tank shows fewer UK gallons.
The water alone is about 1 kg per litre. With glass, substrate and decor a set-up tank typically weighs 20–30% more than its water.
Keep track in Aquairi
Save this tank, log every test in one place and get reminders for water changes and tests. Free, right in your browser.
Save this tank and get reminders → start free