Dimensions, volume, liters and water weight of common aquarium sizes from 5.5 to 125 gallons.
Typical outside dimensions of standard glass aquariums. Manufacturers vary by fractions of an inch, so measure your own tank for exact numbers. Volume here is calculated from the outside dimensions; the water a set-up tank actually holds is usually 10–20% less.
Volume = length × width × height ÷ 231 (cubic inches per US gallon).
Water weight = gallons × 8.34 lb (freshwater). Glass, substrate, rock and the stand come on top; a filled 55 gallon setup typically weighs 500–650 lb in total.
Footprint matters for stands and floors: a heavy tank on a small footprint concentrates the load.