Aquarium Volume Calculator
Water volume of a rectangular tank in liters and gallons.
cm
cm
cm
% of tank height
How it works
Volume in liters = length × width × height × water level in cm ÷ 1,000. Measure the inside of the glass, not the outside. One US gallon is 3.78541 liters. Substrate, rocks, and decor displace water, so the real volume is a little lower than the result, often by 5 to 10 percent. Use the water volume to size heaters, filters, and doses. Example: A 90 × 45 × 50 cm tank filled to 90 percent holds 182.3 liters, or 48.1 US gallons.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.