Free aquarium calculator
Aquarium Tank Weight Calculator
Check whether your floor and stand can take the load. Enter your tank's dimensions and glass thickness to get the empty weight and the full weight with water and substrate.
On the spec sheet, or measure the rim. Typical: 6–10 mm. Leave blank to use a suggested value.
Optional — from the substrate calculator. Added to the full weight.
Tank weight
Full (water, substrate & glass)
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Empty (glass only)
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Enter all three dimensions to estimate the weight.
Results are estimates for a plain glass tank. Braces, trim, rimless thicker glass, rock, and the stand itself add more. When in doubt, assume heavier and confirm your floor can carry a concentrated load.
How the weight calculator works
Enter your tank's length, width, and height, plus the glass thickness, and the calculator estimates the empty weight of the glass and the full weight once it's filled. Add a substrate weight to include the bed. The full figure is what your stand and floor actually have to support — often far more than people expect.
The formula
Empty weight is the glass: a rectangular tank has five panes — a base, two sides, and a front and back — so the glass volume is the total pane area × thickness, times glass density (about 2.5 kg per liter). Full weight adds the water (fresh water is about 1 kg per liter of internal volume) and any substrate. We compute the water volume with the same engine as the volume calculator.
Worked example
A 75 × 30 × 45 cm tank holds about 101 liters, so the water alone weighs around 101 kg (223 lb). With 10 mm glass the panes weigh roughly 33 kg, and a 17 kg gravel bed brings the full load to about 151 kg (333 lb) — versus just 33 kg empty. That's why a tank you can lift empty needs a solid stand and floor once filled.
Stand and floor safety
A filled aquarium concentrates a lot of weight on a small footprint. Make sure the stand is rated for the full weight and sits level, and that the floor can take it — a large tank near 200 kg may need to run across floor joists rather than parallel to them, especially on upper storeys. If you're unsure about an older or upstairs floor, ask a builder.
Weight of common aquarium sizes
Empty and full weight of standard tanks, worked out with the calculator above: plain glass at the suggested thickness, filled to the top with fresh water. Substrate, rock, equipment and the stand are not included, so add those on top. A 5 cm (2 in) sand bed adds about 14 kg to a 60 × 30 cm tank and about 32 kg to a 100 × 40 cm tank.
| Tank | Size (L × W × H) | Volume | Glass | Empty | Full of water |
|---|---|---|---|---|---|
| 10 gal | 20 × 10 × 12 in · 51 × 25 × 30 cm | 39 L · 10.4 US gal | 5 mm | 7 kg / 16 lb | 47 kg / 103 lb |
| 20 long | 30 × 12 × 12 in · 76 × 30 × 30 cm | 71 L · 18.7 US gal | 8 mm | 18 kg / 39 lb | 88 kg / 195 lb |
| 29 gal | 30 × 12 × 18 in · 76 × 30 × 46 cm | 106 L · 28.1 US gal | 8 mm | 24 kg / 53 lb | 130 kg / 287 lb |
| 40 breeder | 36 × 18 × 16 in · 91 × 46 × 41 cm | 170 L · 44.9 US gal | 10 mm | 38 kg / 84 lb | 208 kg / 459 lb |
| 55 gal | 48 × 13 × 21 in · 122 × 33 × 53 cm | 215 L · 56.7 US gal | 10 mm | 51 kg / 113 lb | 266 kg / 587 lb |
| 75 gal | 48 × 18 × 21 in · 122 × 46 × 53 cm | 297 L · 78.5 US gal | 12 mm | 70 kg / 155 lb | 368 kg / 811 lb |
| 125 gal | 72 × 18 × 21 in · 183 × 46 × 53 cm | 446 L · 117.8 US gal | 12 mm | 98 kg / 217 lb | 544 kg / 1,200 lb |
| 40 L | 20 × 10 × 13 in · 50 × 25 × 32 cm | 40 L · 10.6 US gal | 5 mm | 8 kg / 17 lb | 48 kg / 105 lb |
| 63 L | 24 × 12 × 14 in · 60 × 30 × 35 cm | 63 L · 16.6 US gal | 8 mm | 16 kg / 36 lb | 79 kg / 175 lb |
| 101 L | 31 × 14 × 14 in · 80 × 35 × 36 cm | 101 L · 26.6 US gal | 8 mm | 22 kg / 49 lb | 123 kg / 271 lb |
| 200 L | 39 × 16 × 20 in · 100 × 40 × 50 cm | 200 L · 52.8 US gal | 10 mm | 45 kg / 99 lb | 245 kg / 540 lb |
| 300 L | 47 × 20 × 20 in · 120 × 50 × 50 cm | 300 L · 79.3 US gal | 12 mm | 69 kg / 152 lb | 369 kg / 814 lb |
| 450 L | 59 × 20 × 24 in · 150 × 50 × 60 cm | 450 L · 118.9 US gal | 12 mm | 95 kg / 208 lb | 545 kg / 1,200 lb |
Frequently asked questions
- How much does a full fish tank weigh?
- Roughly the glass plus about 1 kg for every liter of water (8.34 lb per US gallon), plus substrate. A 100-liter tank holds around 100 kg of water alone, so the full setup is often 120–150 kg. Enter your dimensions above for a figure for your tank.
- How much does the water alone weigh?
- Fresh water weighs about 1 kg per liter, or 8.34 lb per US gallon. So a 200-liter tank carries roughly 200 kg of water; a 55-US-gallon tank about 209 kg. Saltwater is around 2.5% heavier because of the dissolved salt.
- What glass thickness should I enter?
- Check the manufacturer's spec or measure the rim. Typical tanks use 5 mm for small ones, 8–10 mm for mid-size, and 12 mm or more for large tanks. If you don't know, leave it blank and the calculator suggests a thickness based on the volume.
- Will my floor hold an aquarium?
- Most floors handle small and medium tanks fine, but large tanks concentrate a lot of weight. On upper storeys, position big tanks across the joists and near a load-bearing wall, and consider a builder's advice above roughly 200–300 kg. Always confirm the stand is rated for the full weight.
- Does the stand and equipment add much?
- The stand, rocks, large décor, and a sump can add a meaningful amount on top of glass and water. This calculator covers glass, water, and substrate; add the weight of heavy hardscape and equipment separately when checking against your floor's limit.