Aquarium filled weight calculator

Add up the water, empty tank, gravel, rocks and equipment. Include the stand separately and leave any weight you do not know blank.

For the example, 20 US gal of water alone: 166.9 lb. Each part of the weight ↓

Worked example: 20 US gal of water, nothing else weighed yet. Replace the numbers with yours.

Water and units

A tank from our list (empty weight from the maker)Fills in the empty tank weight only. Enter the water below.

Water in the tankWater unit

Count water in a sump or canister once. Only know the gallons on the label? Work out your water volume →

Component weight unit

Tank and contents

Enter dry component mass; water retained in porous material belongs in the water amount once. Zero means absent or deliberately excluded. Blank means unknown.

Empty aquariumDry substrateDry rocks, wood and decorationDry equipment, lid and light

Below the aquarium

Stand and stored suppliesIncludes separately supported equipment. Do not count the same item above and below.

The water stops below the rim, and gravel and decor take up some of the space, so your tank holds less than its size suggests.

Tank weight vs total on the floor

Water + dry aquarium + contents → tank-and-contents total
Tank-and-contents total + stand and supplies → listed installation load

The tank-and-contents amount collects the load above the stand. Adding the stand and supplies gives the listed load at the installation location. Neither says how that load is distributed through braces, feet, floor joists or the building.

Named manufacturer specifications supply the available empty weights. Unpublished or conflicting weights remain blank. Approximate filled totals and shipping weights are not used as bare-tank weights here. Select the exact model, then confirm its support instructions.

Water density varies with temperature and dissolved material. This freshwater calculator uses a rounded planning density; it is not a marine-salinity or engineering tool. Missing weights make the result partial, not a conservative upper bound.

Match stand support, lid and equipment fit before filling. If you have any doubt about your floor, ask a structural engineer.