The average person uses about 15 to 25 litres when showering and approximately about 50 to 60 litres when bathing. So as you can see showering will save on w … ater and electricity. 6 people found this useful.   Most standard shower heads use 2.5 gallons of water per minute. That would mean in a 10 minute shower, you would use 25 gallons of water. Low-flow shower heads are avail … able to cut down on water consumption and still provide a comfortable shower. There are models available that use 2.0 gallons per minute, and even some that use 1.5 gallons per minute.