Tank size?

[dude17]

Hi everyone. I want to donate to a shelter/sell an aquarium and a terrarium I have. They're the same size, 21.5x11x13.5. So my Q is, what do I tell those interested their size is??

Thanks!

[tropfish]

Thats inches right? The your tank is approxomatly 13.31 gallons. You can use the calculator on the right hand toolbar