How many gallons do I have?

[0scar]

My uncle gave me a tank for a b-day present and told me it was a 55g tank. I never owned anything larger than a 20g before, so I don't know anything when it comes to looking at a tank and knowing the size. For the longest time I believed it was a 55g, until today. I went into a fish store for other reasons and told him I had a 55g, and when he described the size... I figured my tank was larger than that. Then he pointed to a tank in the back, and I said my tank was bigger... and he told me the tank he was pointing at was a 75g. I looked at another tank and told him my tank was as big as that... and he said it was a 125g tank. Now i'm confused, I have no idea how big my tank is... so I just got home and took measurements of my tank and now I'm asking you to tell me if by these numbers you can tell how big my tank is....

12.5" x 19.5" x 48"

how many gallons is my tank?

[Heady]

Technically your tank is 51 gallons. However, tanks are often sold as a slightly higher volume tank than it really is; yours was sold as a 55 gallon.

http://www.garf.org/

[RTR]

12.5 x 19.5 x 48" = 11700 cubic inches

11700/231 cu. in. per gallon = 50.6 nominal gallons.

That is not a standard-sized tank - is it glass or plastic?

[0scar]

It's plastic... and has a black back... thank you peoples for your help....

[Hebdizzle]

how far away were you and the store owner standing from? :)