It is important to know the actual size and volume of your fish tank aquarium for many reasons, the primary one being how many fish you are able to keep in the tank, please see our article on fish tank stocking levels for more detail on this. To calculate the size of the aquarium you must do the following calculation:
Length (cm) x Width (cm) x Height (cm) / 1000 = Size of Aquarium in Litres
120cm x 45cm x 45cm / 1000 = 243 litres
To arrive at this you might need to convert inches to cm which is 1 inch = 2.54cm
12 inches x 2.54 = 30.48cm
Lastly you may wish to convert litres to US Gallons which is 1 litre = 0.264172 US Gallons
60 US Gallons / 0.264172 = 227 litres
I hope this short guide helps you to work out what size tank you are referring to and how big your tank actually is. Don’t forget this is just the volume of tank itself and doesn’t include the volume of any external filter or sump and doesn’t take in to consideration any décor within the aquarium.