How long does it take to get clean in the shower? Is it 10 minutes? Did you know that a 10 minutes shower with a standard shower head can use upwards of 80 gallons of water and generate up to 4 pounds of CO2 emissions? That is not including the energy used to heat the water, unless of course you have solar hot water. How much water do you use? Use the Alliance for Water Efficiency’s water calculator to get an estimate of how much water your household uses. The calculator also compares your estimated water usage to an “average” home and a highly efficient home. A regular shower head uses 7 to 10 gallons a minute, while a water-saving shower head puts out 2 to 4 gallons a minute. An average shower lasts 12 to 15 minutes, resulting in a use of up to 150 gallons per shower. In comparison, a full conventional bathtub uses up to 50 gallons, and a whirlpool tub uses up to 80 gallons. .