Work out elevated tank sizing instantly with clear inputs, formula shown and shareable results.
An elevated tank does two jobs: it balances the difference between a steady pumping rate and the peak hour demand, and it provides static head for residual pressure. Capacity is the larger of one third of daily demand or the volume needed to cover the peak deficit, and tower height is set by the minimum residual pressure plus friction.
Pumping rate
Pumping rate (L/s) = daily demand x 1000 / (pumping hours x 3600)
Balancing volume
Capacity = max(0.33 x daily demand, peak deficit sustained over the peak period)
Variable-speed direct pumping is possible but leaves no buffer against power failure and requires pumps sized for peak hour. A tank allows smaller pumps running steadily at better efficiency plus emergency storage.
The minimum residual pressure at the critical consumer — commonly 17 metres in residential areas — plus friction losses to that point, plus the tank's own operating depth.