Tank Volume Calculator
Enter your tank's dimensions to get its volume in US gallons and liters. Actual water volume runs 10–15% lower once you account for substrate, hardscape, and the fill line.
56.1 gal · 212 L
Estimated water volume after substrate and hardscape: ~47.7–50.5 gal
How it works
A rectangular tank's volume is length × width × height. In inches, divide the result by 231 to get US gallons (231 cubic inches per gallon). In centimeters, divide by 1,000 to get liters. One US gallon is 3.785 liters.
Knowing real volume matters for stocking, dosing, and medication — most dosing instructions assume actual water volume, so overestimating your tank can mean overdosing. The AquaLens app stores your true volume and factors it into dosing and stocking guidance automatically.