FishTankFish tank weight calculator
How much will your aquarium weigh once it's full? Pick your tank, add the gravel and rocks, and this calculator adds up the water, glass and everything in it, so you know what your stand and floor have to hold.
This assumes the tank is filled to the top. Gravel and decor push out some water, so the real weight is a little lower, which leaves you on the safe side. Empty weights are typical for standard glass tanks. Acrylic tanks weigh much less empty, and rimless or thick-glass tanks more. For another size, the empty weight is estimated.
A stand that fits
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The top of the stand must be at least as big as the tank, so every edge of the tank is supported. See how to choose an aquarium stand.
How much does a fish tank weigh?
Water weighs about 8.3 pounds per gallon, so the water alone is most of the weight. Add the glass, gravel and rocks, and a good rule of thumb is about 10 pounds per gallon once a tank is set up. This chart uses the same numbers as the calculator, with 2 inches of gravel:
| Tank | Size | Empty | Water | Set up, full |
|---|---|---|---|---|
| 5.5 gallon | 16 × 8 × 10 in | 7 lb | 45 lb | about 70 lb |
| 10 gallon | 20 × 10 × 12 in | 11 lb | 85 lb | about 120 lb |
| 20 gallon high | 24 × 12 × 16 in | 25 lb | 165 lb | about 225 lb |
| 20 gallon long | 30 × 12 × 12 in | 25 lb | 165 lb | about 235 lb |
| 29 gallon | 30 × 12 × 18 in | 40 lb | 240 lb | about 325 lb |
| 40 gallon breeder | 36 × 18 × 16 in | 58 lb | 335 lb | about 465 lb |
| 55 gallon | 48 × 13 × 21 in | 78 lb | 460 lb | about 610 lb |
| 75 gallon | 48 × 18 × 21 in | 140 lb | 625 lb | about 865 lb |
| 125 gallon | 72 × 18 × 21 in | 206 lb | 1040 lb | about 1400 lb |
Can my floor hold a fish tank?
- Up to about 30 gallons, a tank weighs about as much as a couple of adults, so a sound floor is fine almost anywhere.
- 40 to 55 gallons (450 to 600 pounds) is usually fine too. Put it against an outside or load-bearing wall, with the long side running across the floor joists rather than along one joist.
- 75 gallons and up, or any big tank on an upper floor, in an older home or over a sagging floor, is worth checking with a builder before you fill it.
- A concrete floor on the ground, like a basement or a slab, can take any home aquarium.
What size stand do I need?
Use a stand made for aquariums, rated for at least the total weight above. Regular furniture, bookshelves and dressers aren't built for hundreds of pounds sitting in one spot, and particle board swells and weakens if it gets wet. The stand must be level, and the tank should not hang over any edge. See best aquarium stands.
Related: Aquarium volume calculator · Substrate calculator · How to set up a fish tank