Pet
Aquarium Water Volume Calculator
Calculate aquarium volume in litres and gallons from length, width and height.
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Formula
Volume in litres equals length times width times height in centimetres, divided by 1000.
How it works
Internal dimensions multiply to cubic centimetres, converted to litres. Substrate, rocks and equipment displace water, so usable volume is shown about 10% lower.
FAQs
Should I measure inside or outside?
Inside, since glass thickness reduces real volume.
Why does usable volume matter?
Stocking, dosing and filtration all depend on real water, not glass size.
Are UK and US gallons different?
Yes. This page uses US gallons; UK gallons are larger.
General information only, not veterinary advice.
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