Compare common four-foot aquariums
| Tank | Common dimensions | Water only | Editable empty glass estimate |
|---|---|---|---|
| 40-gallon breeder | 36 × 18 × 16 in | 333.6 lb | 58 lb |
| 55-gallon | 48 × 13 × 21 in | 458.7 lb | 78 lb |
| 75-gallon | 48 × 18 × 21 in | 625.5 lb | 140 lb |
The 55 and 75 gallon tanks can share a similar length, but their front-to-back depth and complete setup weights differ. Compare the exact model, stand, equipment space and room access—not just gallons.
What the full-weight result includes
Inside the tank
Water, substrate, rock, driftwood, decor and livestock displacement assumptions.
Equipment and cabinet
Filter, lid, light, heaters, pumps, sump water, plumbing and the stand itself.
Support check
Stand rating, level contact, water damage, bowing, fasteners, floor condition and footprint.
Assumptions and editable defaults
- Fresh water uses 8.34 lb per US gallon; saltwater uses a 2.5% density increase.
- The 55-gallon planning preset uses 48 × 13 × 21 inches and a 78 lb empty glass tank. Trim, bracing, overflow systems and brand specifications vary.
- The acrylic option applies an approximate lighter empty-tank preset; replace it with the manufacturer’s listed weight.
- Common aquarium charts distinguish empty and filled weights and note that acrylic models weigh less; see the background reference from The Spruce Pets. Always use the exact product data when available.
55-gallon aquarium weight questions
How much does 55 gallons of freshwater weigh?
About 458.7 pounds, or about 208 kilograms. This is water only.
How much does a complete 55-gallon aquarium weigh?
With the editable defaults on this page, the tank, substrate, rock, equipment and stand bring the setup to about 707 pounds before the planning margin.
Can a regular dresser support a 55-gallon aquarium?
Do not assume it can. Aquarium stands are designed around tank dimensions and load paths. Verify the actual support rating and construction before filling.