Most fish keepers call their aquarium by their gallon volume.
| Volume | Length x Width x Height | ||
| Gallon | Litre | Inch | Centimetre |
| 2 1/2 | 9 | 12″ x 6″ x 8″ | 30 x 15 x 20cm |
| 5 | 19 | 16″ x 8″ x 10″ | 40 x 20 x 25cm |
| 10 | 38 | 20″ x 10″ x 12″ | 50 x 25 x 30cm |
| 15 | 57 | 24″ x 12″ x 12″ | 60 x 30 x 30cm |
| 15 | 57 | 20″ x 10″ x 18″ | 50 x 25 x 45cm |
| 20 | 76 | 24″ x 12″ x 16″ | 60 x 30 x 40cm |
| 20 | 76 | 30″ x 12″ x 12″ | 75 x 30 x 30cm |
| 25 | 95 | 24″ x 12″ x 20″ | 60 x 30 x 50cm |
| 29 | 110 | 30″ x 12″ x 18″ | 75 x 30 x 45cm |
| 30 | 114 | 36″ x 18″ x 12″ | 90 x 45 x 30cm |
| 40 | 151 | 36″ x 18″ x 16″ | 90 x 45 x 40cm |
| 40 | 151 | 48″ x 12″ x 16″ | 120 x 30 x 40cm |
| 50 | 189 | 36″ x 18″ x 19″ | 90 x 45 x 47.5cm |
| 55 | 208 | 48″ x 13″ x 21″ | 120 x 32.5 x 52.5cm |
| 65 | 246 | 36″ x 18″ x 24″ | 90 x 45 x 60cm |
| 75 | 284 | 48″ x 18″ x 21″ | 120 x 45 x 52.5cm |
| 90 | 341 | 48″ x 18″ x 24″ | 120 x 45 x 60cm |
| 125 | 473 | 72″ x 18″ x 21″ | 180 x 45 x 52.5cm |
| 150 | 568 | 72″ x 18″ x 28″ | 180 x 45 x 70cm |
| 180 | 681 | 72″ x 24″ x 25″ | 180 x 60 x 62.5cm |
| 225 | 852 | 72″ x 27.5″ x 27.5″ | 180 x 68.75 x 68.75cm |