Work out water tank volume instantly with clear inputs, formula shown and shareable results.
Tank volume follows the geometry: pi r squared h for a cylinder, l x w x h for a rectangle, and four thirds pi r cubed for a sphere. One cubic metre is 1,000 litres and weighs one tonne, which is the figure that matters when siting a tank on a roof or platform.
Tank volume
cylinder = pi r^2 h; rectangular = l w h; sphere = (4/3) pi r^3; 1 m3 = 1000 L = 1 tonne
A modest 2,000 litre loft tank weighs two tonnes when full. That load must be spread across joists or it will fail the ceiling structure.
Yes. Working capacity is usually 90-95% of geometric volume to leave room for the inlet, overflow and any float valve mechanism.