US standard aquarium sizes
North American tanks are sold by nominal gallons. The dimensions are outside measurements (length × width × height) of the glass; framed tanks are about half an inch bigger over the trim. The filled weight is our estimate for water, glass, and a typical load of gravel and decor, without the stand.
| Tank | L × W × H (in) | L × W × H (cm) | Litres | Empty | Filled, about |
|---|---|---|---|---|---|
| 2.5 gallon | 12 × 6 × 8 | 30 × 15 × 20 | 9 | 5 lb2 kg | 30 lb15 kg |
| 5.5 gallon | 16 × 8 × 10 | 41 × 20 × 25 | 21 | 8 lb4 kg | 60 lb30 kg |
| 10 gallon | 20 × 10 × 12 | 51 × 25 × 30 | 38 | 13 lb6 kg | 105 lb50 kg |
| 15 gallon | 24 × 12 × 12 | 61 × 30 × 30 | 57 | 16 lb7 kg | 155 lb70 kg |
| 20 gallon high | 24 × 12 × 16 | 61 × 30 × 41 | 76 | 25 lb11 kg | 205 lb95 kg |
| 20 gallon long | 30 × 12 × 12 | 76 × 30 × 30 | 76 | 19 lb9 kg | 205 lb95 kg |
| 29 gallon | 30 × 12 × 18 | 76 × 30 × 46 | 110 | 39 lb18 kg | 295 lb135 kg |
| 30 gallon breeder | 36 × 18 × 12 | 91 × 46 × 30 | 114 | 27 lb12 kg | 315 lb145 kg |
| 37 gallon | 30 × 12 × 22 | 76 × 30 × 56 | 140 | 61 lb28 kg | 380 lb170 kg |
| 40 gallon breeder | 36 × 18 × 16 | 91 × 46 × 41 | 151 | 42 lb19 kg | 405 lb185 kg |
| 40 gallon long | 48 × 12 × 16 | 122 × 30 × 41 | 151 | 52 lb24 kg | 410 lb185 kg |
| 55 gallon | 48 × 13 × 21 | 122 × 33 × 53 | 208 | 89 lb40 kg | 570 lb260 kg |
| 65 gallon | 36 × 18 × 24 | 91 × 46 × 61 | 246 | 90 lb41 kg | 650 lb295 kg |
| 75 gallon | 48 × 18 × 21 | 122 × 46 × 53 | 284 | 102 lb46 kg | 755 lb345 kg |
| 90 gallon | 48 × 18 × 24 | 122 × 46 × 61 | 341 | 140 lb64 kg | 910 lb415 kg |
| 120 gallon | 48 × 24 × 24 | 122 × 61 × 61 | 454 | 161 lb73 kg | 1,190 lb540 kg |
| 125 gallon | 72 × 18 × 21 | 183 × 46 × 53 | 473 | 142 lb64 kg | 1,220 lb555 kg |
| 150 gallon | 72 × 18 × 28 | 183 × 46 × 71 | 568 | 265 lb120 kg | 1,535 lb695 kg |
| 180 gallon | 72 × 24 × 25 | 183 × 61 × 64 | 681 | 228 lb103 kg | 1,770 lb805 kg |
| 210 gallon | 72 × 24 × 29 | 183 × 61 × 74 | 795 | 305 lb138 kg | 2,080 lb945 kg |
Metric aquarium sizes
In Europe, the UK and Australia, tanks are sold by their dimensions in centimetres or by litres. These are the sizes most often stocked.
| Tank (cm) | In inches | Litres | US gallons | Filled, about |
|---|---|---|---|---|
| 30 cube | 11.8 × 11.8 × 11.8 | 27 | 7 | 35 kg75 lb |
| 40 × 25 × 25 | 15.7 × 9.8 × 9.8 | 25 | 7 | 35 kg75 lb |
| 45 × 27 × 30 | 17.7 × 10.6 × 11.8 | 36 | 10 | 45 kg105 lb |
| 60 × 30 × 30 | 23.6 × 11.8 × 11.8 | 54 | 14 | 70 kg150 lb |
| 60 × 30 × 36 | 23.6 × 11.8 × 14.2 | 65 | 17 | 80 kg175 lb |
| 60 × 45 × 45 | 23.6 × 17.7 × 17.7 | 122 | 32 | 145 kg315 lb |
| 80 × 35 × 40 | 31.5 × 13.8 × 15.7 | 112 | 30 | 135 kg300 lb |
| 90 × 45 × 45 | 35.4 × 17.7 × 17.7 | 182 | 48 | 215 kg480 lb |
| 100 × 40 × 40 | 39.4 × 15.7 × 15.7 | 160 | 42 | 190 kg420 lb |
| 100 × 40 × 50 | 39.4 × 15.7 × 19.7 | 200 | 53 | 245 kg540 lb |
| 120 × 40 × 50 | 47.2 × 15.7 × 19.7 | 240 | 63 | 290 kg645 lb |
| 120 × 45 × 45 | 47.2 × 17.7 × 17.7 | 243 | 64 | 290 kg635 lb |
| 120 × 50 × 50 | 47.2 × 19.7 × 19.7 | 300 | 79 | 360 kg795 lb |
| 150 × 50 × 50 | 59.1 × 19.7 × 19.7 | 375 | 99 | 445 kg985 lb |
| 150 × 60 × 60 | 59.1 × 23.6 × 23.6 | 540 | 143 | 640 kg1,410 lb |
| 180 × 60 × 60 | 70.9 × 23.6 × 23.6 | 648 | 171 | 765 kg1,685 lb |
How to read the names
- Long and high. A "20 long" and a "20 high" hold the same volume, but the long is 30 inches wide and the high is 24. Long tanks have more floor and surface area and suit most fish better.
- Breeder. The 30 and 40 gallon "breeder" tanks are low and wide, 18 inches from front to back. That shape gives the most floor for the volume, which is why breeders, aquascapers and reef keepers all like them.
- Nominal gallons. The name is a round figure. Measure the glass and you will find a "55 gallon" holds 56.7 gallons brim-full and about 46 gallons of actual water once it is set up. The volume calculator shows the real figure for your tank.
Which size for which fish
| Tank | Suits |
|---|---|
| 5 gallon (19 L) | One betta, or a shrimp colony |
| 10 gallon (38 L) | A group of very small fish (ember tetras, chili rasboras, Endlers), or a betta with shrimp and snails |
| 20 gallon (76 L) | A small community: tetras or rasboras, corydoras, one centrepiece fish |
| 29–40 gallon (110–150 L) | A full community; dwarf cichlids; one fancy goldfish in a 30 or 40 |
| 55 gallon (208 L) | Larger communities, angelfish, rainbowfish, African cichlids |
| 75 gallon (284 L) and up | Oscars and other large cichlids, big schools, goldfish groups |
To check a specific mix of fish, use the stocking calculator.
Before you buy
Measure the space, including room behind the tank for the filter and cables and above it for your arm and a net. Check that the stand matches the footprint exactly, and that the floor can carry the weight in the last column: the weight calculator breaks it down and explains what timber floors can take.
Questions and answers
What are the dimensions of a 40 gallon breeder?
A 40 gallon breeder is 36 × 18 × 16 inches (91 × 46 × 41 cm). It has the same floor area as a 65-gallon tank.
What are the dimensions of a 75 gallon tank?
A standard 75-gallon aquarium is 48 × 18 × 21 inches (122 × 46 × 53 cm): the same length and height as a 55-gallon, but 5 inches deeper front to back.
What is the difference between a 20 gallon long and a 20 gallon high?
The 20 long is 30 × 12 × 12 inches; the 20 high is 24 × 12 × 16 inches. Same volume, but the long has 25% more floor and water surface.
How many litres is a 4 foot tank?
It depends on width and height. The common 120 × 40 × 50 cm tank holds 240 litres brim-full; a 120 × 45 × 45 cm tank holds 243 litres; the US 55-gallon (48 × 13 × 21 in) holds about 215 litres.