To calculate the capacity of a water tank we will find the volume of the water tank in cubic meters and multiply it by 1000 to convert it into litre.

**How to calculate the capacity of a rectangular water tank?**

For the capacity of a rectangular water tank we calculate the volume of the rectangular water tank L✕B✕H in cubic metre and multiply it by 1000 to convert it into litre.

Let us take an example for better understanding:

Q- The length, breadth, and height of a rectangular water tank are 4m, 2m, and 3m respectively. Find its volume and capacity in litres.

Solve:

Volume of a rectangular tank formula = L✕B✕H

= L✕B✕H

= 4m✕2m✕3m

= 24 cubic metres.

The capacity of rectangular water tank = Volume of tank✕1000

= Volume of tank✕1000

= L✕B✕H✕1000

= 4m✕2m✕3m✕1000

= 24✕1000

= 24000 litres.

**How to calculate the capacity of a circular water tank?**

To calculate the capacity of a circular water tank we will find the volume of cylinder Ï€r²h in cubic metres and multiply it by 1000 to convert it into litre.

Take an example for better understanding:

Q- Calculate the volume and capacity of a circular water tank of radius 2m and height 7m.

Solve:

The volume of cylindrical tank formula = Ï€r²h

= Ï€r²h

= 22/7✕2✕2✕7

= (22✕2✕2✕7)/7

= 88 cubic meter

The capacity of circular water tank = Ï€r²h✕1000

= Ï€r²h✕1000

= 22/7✕2✕2✕7✕1000

= (22✕2✕2✕7✕1000)/7

= 88000 litres