How to calculate water tank capacity in liters?

Let us suppose your tank dimensions are 

L = 8ft

B = 6 ft

D/H = 5 ft

Then your volume of tank will be 

8 x 6 x 5 = 240 ft³

Now 1ft³ = 28.31 liter,

hence, total volume of tank in liter shall be 240 x 28.31 = 6794.4 liter. 

That means almost 6800 liter of water can be stored in the tank. 

Here is a quick video to show you How to calculate water tank capacity in liters?