What size water heater should I buy?

Most people base their purchases on the size of the storage tank, but a better method is to first estimate how much hot water you will need during the peak hour of use. This is referred to as the first-hour rating (FHR) on the Energy Guide label posted on new water heaters. Typical hot water use is:

   * Showering 3 gallons/minute
   * Bathing 15-25 gallons per bath
   * Shaving 1-3 gallons
   * Washing hands 1/2-2 gallons
   * Washing dishes 4-6 gallons
   * Running dishwasher 5-20 gallons
   * Running clothes washer 25-40 gallons
   * Cleaning house 5-12 gallons
   * Food preparation 1-6 gallons