Shower Water Calculator

A shower water calculator shows litres per shower and annual usage. Standard shower heads use 8–12 L/min; water-efficient models use 6–8 L/min

The calculator uses the standard published formula for shower water. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches, litres, percentages, watts. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: Litres per shower = Duration (min) × Flow rate (L/min). Each step in the calculation is shown so you can verify the result manually.