Energy Saver Calculator – Home Energy Costs
     First tell us some key facts about your home energy costs: 
     Use these national averages, or enter your own costs. 
    
     kWh = killowat-hour, a measure of electricity use.  Ten 100-watt light bulbs on for 1 hour use 1 kWh of electricity. 
    
     A therm is a measure of natural gas, about 100 cubic feet. 
     If you do not use gas, leave this box empty.