Knowing your aquarium’s true volume matters for dosing medicine, choosing a filter and heater, and checking your stand can take the weight. This free fish tank volume calculator works out gallons and litres for rectangle, cylinder, hexagon and bow-front tanks. It allows for the fill level and for decor and gravel, and shows the water weight and a rough filter and heater size.
How to use:
- Choose your tank shape and measuring unit.
- Enter the dimensions and the glass height.
- Set how full the tank is and how much space decor and gravel take.
- Click Calculate for litres, US and UK gallons and water weight.
FAQs:
Q: How do I calculate aquarium volume?
A: For a rectangular tank, multiply length × width × height. Divide cubic inches by 231 for US gallons, or cubic centimetres by 1,000 for litres.
Q: Why is my real water volume less than the tank’s rated size?
A: You never fill to the rim, and gravel, rocks and decor take up space. The calculator allows for both.
Q: How much does a fish tank weigh?
A: Water alone weighs about 1 kg per litre (8.3 lb per US gallon). A 55-gallon tank holds over 200 kg of water before the glass, stand and decor.
Q: What size filter do I need?
A: A common guide is a filter that turns the tank’s water over 4 to 5 times an hour. The calculator shows that flow rate in litres per hour.
