INTERNAL NATURE
Aquarium Volume Calculator
Estimate your aquarium’s true water volume, including fill depth and space taken up by substrate, rock, wood, decor, and filter space.
ESTIMATED REAL WATER VOLUME
Most aquariums hold less water than their advertised volume once substrate, hardscape, filters, and lower fill lines are included.
Use the water height, not the full glass height.
Substrate & hardscape displacement
0%This is a rough visual guide: more substrate, rocks, wood, and filter space means less actual water volume.
ESTIMATED REAL WATER VOLUME
Most aquariums hold less water than their advertised volume once substrate, hardscape, filters, and lower fill lines are included.
Why real water volume matters
Knowing the actual water volume helps with water changes, medication, fertiliser dosing, salt use, and understanding how much stable water your aquarium really contains.