Aquarium Volume: Litres Before Fish
Tank size decides almost everything else in fishkeeping, from how many fish fit to how much treatment to dose. Measuring it first avoids guesswork later.
What is the Aquarium Volume Calculator?
Enter the tank's internal dimensions in centimetres and the tool gives volume in litres and US gallons. This is a plain volume calculation, and real water volume will be slightly less once substrate and decorations are added.
How to use it
- Enter length, width, and height in centimetres.
- Click Calculate Aquarium Volume.
- Use the volume for stocking and dosing guides.
Worked example
A 60 by 30 by 40 cm tank holds 72 litres, or about 19.02 US gallons.
Why use internal dimensions?
External measurements include glass thickness, which overstates water volume. Internal dimensions give the water space itself.
Frequently asked questions
Does substrate reduce volume?
Yes, slightly. Gravel and decorations displace water, so treat the result as a maximum.
Are US and UK gallons different?
Yes. This tool uses US gallons; a UK gallon is larger, so do not mix the two when dosing.