Aquarium Tank Weight Calculator

How this calculator works

Dimensions are converted to US gallons. Freshwater is estimated at 8.34 lb per gallon and saltwater at 8.55 lb per gallon. Empty tank weight is approximated from volume, with glass heavier than acrylic.

Substrate and rock are added after converting the entered units to pounds, then the final total is shown in both pounds and kilograms.

Why it matters

Filled aquariums are heavy static loads. A stand rated for a dry tank or a piece of household furniture is not the same as a stand rated for a filled aquarium with water, substrate, rock, and equipment.

Worked example

A 48 by 18 by 21 inch freshwater glass aquarium holds roughly 79 US gallons by gross dimensions. Water alone is about 660 lb; substrate, rock, and the empty tank can push the filled system well above that.

FAQ

Is the empty tank weight exact?

No. It is a practical estimate from volume and material; manufacturer specifications are better when available.

Why is saltwater heavier?

Dissolved salts increase density, so the calculator uses about 8.55 lb per US gallon for saltwater instead of 8.34 for freshwater.

Does this check my floor structure?

No. It only estimates total weight. Large systems need stand and floor support review.

Should I include equipment weight?

Yes, add heavy canopies, sumps, rocks, or external equipment separately if they are supported by the same stand or floor area.